1, git.bmp
"Salivary amylase is secreted by the tongue."
"F"
"Salivary amylase is secreted by the salivary glands."
"Salivary amylase is secreted by the salivary glands."
"T"
"Salivary amylase is secreted by the salivary glands."
2, git.bmp
"Salivary amylase catalyses the hydrolysis of triacylglycerols to liberate free fatty acids."
"F"
"Salivary amylase catalyses the hydrolysis of starch to dextrins, glucose, maltose and isomaltose."
"Salivary amylase catalyses the hydrolysis of starch."
"T"
"Salivary amylase catalyses the hydrolysis of starch to dextrins, glucose, maltose and isomaltose."
3, git.bmp
"Lingual lipase is secreted by the tongue."
"T"
"Lingual lipase is secreted by the tongue."
"Lingual lipase is secreted by the salivary glands."
"F"
"Lingual lipase is secreted by the tongue."
4, git.bmp
"Lingual lipase catalyses the hydrolysis of triacylglycerols to liberate free fatty acids."
"T"
"Lingual lipase catalyses the hydrolysis of triacylglycerols to liberate free fatty acids."
"Lingual lipase catalyses the hydrolysis of starch."
"F"
"Lingual lipase catalyses the hydrolysis of triacylglycerols to liberate free fatty acids."
5, git.bmp
"Gastric acid is important in the denaturation of proteins."
"T"
"Denaturation is important to permit proteolytic enzymes to gain access to peptide bonds in proteins, and gastric acid is important in denaturing proteins."
"Gastric acid activates pepsinogen to pepsin."
"T"
"Pepsin is secreted as an inactive precursor (a zymogen) and is activated by either gastric acid or pre-existing pepsin."
6, git.bmp
"Protein hydrolysis begins in the stomach."
"T"
"Pepsin is the first of the proteolytic enzymes; it is an endopeptidase."
"Triacylglycerols are hydrolysed in the stomach."
"T"
"Lipase secreted by the gastric mucosa catalyses the hydrolysis of triacylglycerols."
7, git.bmp
"A protein secreted in the gastric juice is important for the absorption of vitamin B12."
"T"
"Intrinsic factor is a vitamin B12-binding protein secreted by the gastric mucosa, which is essential for the absorption of vitamin B12."
"Achlorhydria may lead to vitamin B12 deficiency."
"T"
"Achlorhydria (failure of secretion of gastric acid) may lead to failure of vitamin B12 absorption, for two reasons: (a) gastric acid is important to release vitamin B12 that is bound to proteins in foods; (b) intrinsic factor is secreted by the same cells as secreted gastric acid, and loss of these cells leads to loss of both acid secretion and intrinsic factor secretion."
8, git.bmp
"Amylase is secreted by the pancreas into the small intestine."
"T"
"Most digestion of starch occurs in the small intestine, catalysed by pancreatic amylase."
"Amylase is secreted by the pancreas into stomach."
"F"
"The exocrine pancreas secretes enzymes into the small intestine, not the stomach."
9, git.bmp
"The endocrine cells of the pancreas secrete enzymes into the small intestine."
"F"
"It is the exocrine cells of the pancreas that secrete enzymes into the small intestine; the endocrine cells secrete hormones into the bloodstream."
"The exocrine cells of the pancreas secrete enzymes into the small intestine."
"T"
"The exocrine cells of the pancreas secrete enzymes into the small intestine; the endocrine cells secrete hormones into the bloodstream."
10, git.bmp
"Pancreatic lipase catalyses the hydrolysis of starch."
"F"
"Pancreatic lipase catalyses the hydrolysis of triacylglycerols."
"Pancreatic lipase catalyses the hydrolysis of disaccharides."
"F"
"Pancreatic lipase catalyses the hydrolysis of triacylglycerols."
11, villus.bmp
"Disaccharides are hydrolysed in the lumen of the small intestine."
"F"
"Disaccharides are hydrolysed by disaccharidases in the brush border of the small intestinal mucosal cells."
"Triacylglycerols are hydrolysed by lipase in the brush border of the small intestinal mucosal cells."
"F"
"Triacylglycerols are hydrolysed in the lumen of the small intestine, by lipase secreted by the pancreas."
12, git.bmp
"Endopeptidases catalyse the hydrolysis of the terminal (end) amino acids of proteins."
"F"
"Endopeptidases catalyse hydrolysis of peptide bonds within the protein molecule, not at the terminals."
"Exopeptidases catalyse the hydrolysis of the terminal (end) amino acids of proteins."
"T"
"Exopeptidases catalyse the hydrolysis of terminal amino acids from proteins and peptides."
13, git.bmp
"The small intestine is the site of absorption of most of the products of digestion of proteins, lipids and carbohydrates."
"T"
"Most absorption occurs in the small intestine."
"Water is absorbed in the small intestine."
"T"
"A very large volume of water is secreted into the gastro-intestinal tract, and most of this is re-absorbed in the small intestine."
14, git.bmp
"Some of the protein that is hydrolysed in the small intestine does not come from the diet."
"T"
"A significant amount of protein, as much as, or rather more than, the dietary intake, is either secreted into the gastro-intestinal tract or comes from shed intestinal mucosal cells. Most of this is hydrolysed by proteolytic enzymes and the amino acids absorbed."
"Only protein from the diet is hydrolysed in the small intestine."
"F"
"A significant amount of protein, as much as, or rather more than, the dietary intake, is either secreted into the gastro-intestinal tract or comes from shed intestinal mucosal cells. Most of this is hydrolysed by proteolytic enzymes and the amino acids absorbed."
15, git.bmp
"Bacteria in the large intestine ferment undigested carbohydrates."
"T"
"Intestinal bacterial fermentation of undigested carbohydrates leads to formation of significant amounts of short-chain fatty acids, some of which have anti-proliferative actions and may help to prevent colo-rectal cancer."
"Bacteria in the large intestine ferment undigested carbohydrates."
"T"
"Intestinal bacterial fermentation of undigested carbohydrates leads to formation of significant amounts of short-chain fatty acids, some of which have anti-proliferative actions and may help to prevent colo-rectal cancer."
16,villus.bmp
"The diagram shows a small intestinal villus. Mucosal cells are proliferating in region A."
"F"
"The mucosal cells proliferate in the crypts (region E), and undergo apoptosis (programmed cell death) and are shed at the tip of the villus (region A)."
"The diagram shows a small intestinal villus. Mucosal cells are proliferating in region E."
"T"
"The mucosal cells proliferate in the crypts (region E), and undergo apoptosis (programmed cell death) and are shed at the tip of the villus (region A)."
17, villus.bmp
"The diagram shows a small intestinal villus. Mucosal cells are undergoing apoptosis (programmed cell death) and being shed in region E."
"F"
"The mucosal cells proliferate in the crypts (region E), and undergo apoptosis (programmed cell death) and are shed at the tip of the villus (region A)."
"The diagram shows a small intestinal villus. Mucosal cells are undergoing apoptosis (programmed cell death) and being shed in region A."
"T"
"The mucosal cells proliferate in the crypts (region E), and undergo apoptosis (programmed cell death) and are shed at the tip of the villus (region A)."
18, villus.bmp
"The diagram shows a small intestinal villus. Label B is pointing to the central blood vessel of the villus."
"F"
"Label B is pointing to the lacteal, which is part of the lymphatic system, not the bloodstream."
"The diagram shows a small intestinal villus. Label B is pointing to the lacteal."
"T"
"The lacteal is part of the lymphatic system, not the bloodstream."
19, villus.bmp
"The diagram shows a small intestinal villus. Label C is pointing to the lacteal."
"F"
"Label C is pointing to the mucosal epithelium, which contains both absorptive and secretory cells."
"The diagram shows a small intestinal villus. Goblet cells in region C secrete mucus that protects the intestinal mucosa from digestion by secreted enzymes."
"T"
"Intestinal mucus is important to protect the mucosa from digestion by the proteolytic enzymes secreted into the intestinal lumen; mucin, the main protein of mucus, is very resistant to the action of proteolytic enzymes. Mucus secretion accounts for a significant proportion of protein requirements."
20, villus.bmp
"The diagram shows a small intestinal villus. Label D is pointing to the lacteal."
"F"
"Label D is pointing to a capillary blood vessel, not the lacteal."
"The diagram shows a small intestinal villus. Label D is pointing to a capillary blood vessel.
"T"
"Label D is indeed pointing to the capillary blood system of the villus."
21, villus.bmp
"The products of protein digestion are absorbed across the intestinal mucosa into the lacteal."
"F"
"The products of protein digestion are absorbed across the intestinal mucosa into the capillary blood vessels."
"The products of carbohydrate digestion are absorbed across the intestinal mucosa into the lacteal."
"F"
"The products of carbohydrate digestion are absorbed across the intestinal mucosa into the capillary blood vessels."
22, villus.bmp
"The products of triacylglycerol digestion are free fatty acids that are absorbed across the intestinal mucosa into the capillary blood vessels."
"F"
"The free fatty acids that result from triacylglycerol digestion are re-esterified to triacylglycerol in the intestinal mucosal cells, then assembled into chylomicrons, which are secreted into the lacteal, not the capillary blood vessels."
"The products of triacylglycerol digestion are free fatty acids that are absorbed across the intestinal mucosa into the lacteal."
"F"
"The free fatty acids that result from triacylglycerol digestion are re-esterified to triacylglycerol in the intestinal mucosal cells, then assembled into chylomicrons, which are secreted into the lacteal."
23, villus.bmp
"The diagram shows a small intestinal villus. The lacteal (labelled 'B') drains into the hepatic portal vein."
"F"
"The lacteal is part of the lymphatic system, which enters the bloodstream at the thoracic duct."
"The diagram shows a small intestinal villus. The capillary blood vessel (labelled D) drains into the hepatic portal vein."
"T"
"The blood vessels draining the small and large intestine join the hepatic portal vein, and the entry of the products of digestion of carbohydrate and protein into the peripheral circulation is controlled by the liver."
24, villus.bmp
"The products of lipid absorption enter the hepatic portal vein, and their entry into the peripheral circulation is controlled by the liver."
"F"
"The products of lipid absorption enter the lacteal, and then the lymphatic system, which enters the bloodstream at the thoracic duct. This means that absorbed lipids enter the peripheral circulation uncontrolled by the liver, which takes up the chylomicron remnants."
"The products of protein digestion enter the hepatic portal vein, and their entry into the peripheral circulation is controlled by the liver."
"T"
"Amino acids and monosaccharides are absorbed into the capillary blood vessels, which join the hepatic portal vein, and the entry of the products of digestion of carbohydrate and protein into the peripheral circulation is controlled by the liver."
25, starch.bmp
"The diagram shows part of a molecule of starch. The bond between two glucose units in region C is a 1-4 glycoside bond."
"T"
"This is indeed a 1-4 glycoside bond - between carbon 1 of one glucose unit and carbon 4 of the next."
"The diagram shows part of a molecule of starch. The bond between two glucose units in region B is a 1-4 glycoside bond."
"F"
"This is a 1-6 glycoside bond - between carbon 1 of one glucose unit and carbon 6 of the next. This type of bond forms a branch point in starch (and also in glycogen)."
26, starch.bmp
"The diagram shows part of a molecule of starch. Amylase catalyses sequential hydrolysis and release of single glucose units (as shown in region A)."
"F"
"Amylase catalyses random hydrolysis of glycoside bonds in starch, leading to formation of glucose, maltose (as in region C) and isomaltose (as in region B)."
"The diagram shows part of a molecule of starch. Amylase catalyses random hydrolysis of glycoside bonds in starch."
"T"
"Amylase catalyses random hydrolysis of glycoside bonds in starch, leading to formation of glucose (as in region A), maltose (as in region C) and isomaltose (as in region B)."
27, starch.bmp
"The diagram shows part of a molecule of starch. Amylase action will result in the release of glucose, maltose and isomaltose. Region A is maltose."
"F"
"Region A is a single monosaccharide unit - glucose."
"The diagram shows part of a molecule of starch. Amylase action will result in the release of glucose, maltose and isomaltose. Region A is glucose."
"T"
"Region A is a single monosaccharide unit - glucose."
28, starch.bmp
"The diagram shows part of a molecule of starch. Amylase action will result in the release of glucose, maltose and isomaltose. Region B is maltose."
"F"
"Region B is isomaltose, with a 1-6 glycoside bond."
"The diagram shows part of a molecule of starch. Amylase action will result in the release of glucose, maltose and isomaltose. Region B is isomaltose."
"T"
"Region B is isomaltose, with a 1-6 glycoside bond."
29, starch.bmp
"The diagram shows part of a molecule of starch. Amylase action will result in the release of glucose, maltose and isomaltose. Region C is maltose."
"T"
"Region C is maltose, with a 1-4 glycoside bond."
"The diagram shows part of a molecule of starch. Amylase action will result in the release of glucose, maltose and isomaltose. Region C is isomaltose."
"F"
"Region C is maltose, with a 1-4 glycoside bond."
30, blank.bmp
"Intrinsic sugars are dietary essentials."
"F"
"Intrinsic sugars are sugars contained within plant cell walls in foods; they are not dietary essentials."
"Extrinsic sugars are dietary essentials."
"F"
"Extrinsic sugars are sugars in free solution in foods (as opposed to intrinsic sugars, which are within plant cell walls in foods). They are not dietary essentials."
31, fructose.bmp
"This is a pentose sugar."
"F"
"This is fructose - it has 6 carbon atoms, and hence is a hexose sugar, although it forms a 5-membered ring."
"This is a hexose sugar."
"T"
"This is fructose - it has 6 carbon atoms, and hence is a hexose sugar, although it forms a 5-membered ring."
32, ribose.bmp
"This is a pentose sugar."
"T"
"This is ribose - it has 5 carbon atoms and hence is a pentose sugar."
"This is a hexose sugar."
"F"
"This is ribose - it has 5 carbon atoms and hence is a pentose sugar."
33, deoxyrib.bmp
"This is a pentose sugar."
"T"
"This is deoxyribose - it has 5 carbon atoms and hence is a pentose sugar."
"This is a hexose sugar."
"F"
"This is deoxyribose - it has 5 carbon atoms and hence is a pentose sugar."
34, glucose.bmp
"This is a pentose sugar."
"F"
"This is glucose - it has 6 carbon atoms, and hence is a hexose sugar."
"This is a hexose sugar."
"T"
"This is glucose - it has 6 carbon atoms, and hence is a hexose sugar."
35, glucose2.bmp
"This is a sugar alcohol."
"F"
"This is glucose. It has an aldehyde group at carbon-1."
"This is a reducing sugar."
"T"
"This is glucose. It has an aldehyde group at carbon-1, which acts as a reducing agent."
36, sorbitol.bmp
"This is a sugar alcohol."
"T"
"This is sorbitol; it has an alcohol (-OH) group at carbon-1."
"This is a reducing sugar."
"F"
"This is sorbitol; it has an alcohol (-OH) group at carbon-1, and no group that can act as a reducing agent."
37, fructose.bmp
"This compound will be oxidized by glucose oxidase."
"F"
"This is fructose. Glucose oxidase is specific for glucose, and will not react with any other monosaccharide."
"This compound will react with an alkaline copper reagent."
"F"
"This is fructose, which has a ketone group at carbon-2; therefore it is not a reducing compound."
38, sorbitol.bmp
"This compound will reduce an alkaline copper reagent."
"F"
"This is sorbitol, a sugar alcohol. There is no reducing group in this compound, so it will not react with an alkaline copper reagent."
"This compound will be oxidized by glucose oxidase."
"F"
"This is sorbitol. Glucose oxidase is specific for glucose, and will not react with any other monosaccharide."
39, sorbitol.bmp
"This compound is absorbed by active transport in the small intestine."
"F"
"This is sorbitol, a sugar alcohol. Only glucose and galactose are absorbed by sodium-dependent active transport; other monosaccharides are absorbed by facilitated diffusion."
"This compound is absorbed by facilitated diffusion in the small intestine."
"T"
"This is sorbitol, a sugar alcohol. Only glucose and galactose are absorbed by sodium-dependent active transport; other monosaccharides are absorbed by facilitated diffusion."
40, ribose.bmp
"This compound is a pentose (5-carbon sugar)."
"T"
"This is ribose, a 5-carbon sugar."
"This compound is absorbed in the small intestine by sodium-dependent active transport."
"F"
"This is ribose. Only glucose and galactose are absorbed by sodium-dependent active transport; other monosaccharides are absorbed by facilitated diffusion."
41, deoxyrib.bmp
"This compound is a pentose (5-carbon sugar)."
"T"
"This is deoxyribose, a 5-carbon sugar."
"This compound is absorbed in the small intestine by sodium-dependent active transport."
"F"
"This is deoxyribose. Only glucose and galactose are absorbed by sodium-dependent active transport; other monosaccharides are absorbed by facilitated diffusion."
42, deoxyrib.bmp
"This compound is important in the structure of DNA."
"T"
"This is deoxyribose, whose main importance is in the structure of DNA."
"This compound is important in the structure of RNA."
"F"
"This is deoxyribose, whose main importance is in the structure of DNA. In RNA the sugar is ribose, not deoxyribose."
43, ribose.bmp
"This compound is important in the structure of DNA."
"F"
"This is ribose, whose main importance is in the structure of RNA. The sugar in DNA is deoxyribose."
"This compound is important in the structure of RNA."
"T"
"This is ribose, whose main importance is in the structure of RNA and nucleotides."
44, blank.bmp
"All monosaccharides are absorbed from the small intestine by active transport."
"F"
"Only glucose and galactose are absorbed by active transport - other monosaccharides are absorbed by facilitated diffusion."
"Disaccharides are hydrolysed by enzymes in the brush border of the intestinal mucosa."
"T"
"The disaccharidases are brush border enzymes."
45, blank.bmp
"Starch is hydrolysed by amylase, which yields a mixture of glucose, maltose, isomaltose and dextrins."
"T"
"Amylase hydrolyses 1-4 glycoside bonds in starch randomly, so that the end-product is a mixture of glucose, maltose, isomaltose and dextrins."
"Glycogen is hydrolysed by glycogen phosphorylase, yielding glucose 6-phosphate."
"F"
"The reaction of glycogen phosphorylase is not a hydrolysis, but cleavage of the glycoside bond by phosphate (a phosphorolysis) and the product is glucose 1-phosphate, not glucose 6-phosphate."
46, blank.bmp
"Starch is hydrolysed by amylase, yielding glucose 6-phosphate."
"F"
"Amylase hydrolyses starch in such a way as to release a mixture of dextrins (oligosaccharides) plus glucose, maltose and isomaltose. There is no involvement of phosphate in the reaction."
"Starch is hydrolysed by amylase, yielding glucose 1-phosphate."
"F"
"Amylase hydrolyses starch in such a way as to release a mixture of dextrins (oligosaccharides) plus glucose, maltose and isomaltose. There is no involvement of phosphate in the reaction."
47, blank.bmp
"Monosaccharides are hydrolysed by enzymes in the brush border of the intestinal mucosa."
"F"
"By definition, monosaccharides cannot be hydrolysed."
"Disaccharides are absorbed from the small intestine by facilitated diffusion."
"F"
"Disaccharides are not normally absorbed intact to any significant extent, but must be hydrolysed to their constituent monosaccharides. Significant amounts of disaccharides will only be absorbed if there is intestinal mucosal damage leading to 'leakiness' and the uptake of material by diffusion between mucosal cells."
48, blank.bmp
"Glucose and galactose are absorbed from the small intestine by sodium-dependent active transport."
"T"
"Glucose and galactose are absorbed by active transport - other monosaccharides are absorbed by facilitated (passive) diffusion."
"Glucose and galactose are absorbed from the small intestine by facilitated diffusion."
"F"
"Glucose and galactose are absorbed by active transport - other monosaccharides are absorbed by facilitated (passive) diffusion."
49. blank.bmp
"Glycogen is hydrolysed by glycogen phosphorylase, yielding glucose 1-phosphate."
"F"
"The reaction of glycogen phosphorylase is not a hydrolysis, but cleavage of the glycoside bond by phosphate (phosphorolysis). The product of glycogen phosphorylase is indeed glucose 1-phosphate."
"Glycogen is hydrolysed by glycogen phosphorylase, yielding glucose 6-phosphate."
"F"
"The reaction of glycogen phosphorylase is not a hydrolysis, but cleavage of the glycoside bond by phosphate (phosphorolysis). The product of glycogen phosphorylase is glucose 1-phosphate."
50, blank.bmp
"Glycogen is hydrolysed by amylase, yielding glucose 6-phosphate."
"F"
"While any glycogen in the diet may be a substrate for amylase, the product of hydrolysis will not be glucose 6-phosphate, since amylase yields a mixture of glucose, maltose and isomaltose. Phosphorylation is not involved in amylase action."
"Glycogen is hydrolysed by amylase, yielding glucose 1-phosphate."
"F"
"While any glycogen in the diet may be a substrate for amylase, the product of hydrolysis will not be glucose 6-phosphate, since amylase yields a mixture of glucose, maltose and isomaltose. Phosphorylation is not involved in amylase action."
51, blank.bmp
"Fructose is absorbed from the small intestine by facilitated diffusion."
"T"
"Only glucose and galactose are absorbed by active transport - other monosaccharides are absorbed by facilitated diffusion."
"Sugar alcohols are absorbed from the small intestine by facilitated diffusion."
"T"
"Only glucose and galactose are absorbed by active transport - other monosaccharides are absorbed by facilitated diffusion."
52, blank.bmp
"Alactasia (lactose intolerance) can be diagnosed by the appearance of hydrogen in exhaled air after a test dose of lactose."
"T"
"Intestinal bacteria ferment unabsorbed sugars, and hydrogen is one of the products; small amounts diffuse into the bloodstream, and exhaled hydrogen after a small test dose of lactose can provide a very sensitive test of lactase activity."
"Alactasia can be diagnosed by the lack of increase in blood glucose after a test dose of lactose."
"T"
"However, this is relatively insensitive, and requires the subject to take a relatively large dose of lactose - sufficient to cause severe abdominal pain, and diarrhoea, in a subject with alactasia. A more sensitive test uses a very much lower dose of lactose, and measures hydrogen, arising from intestinal bacterial fermentation, in exhaled air."
53, blank.bmp
"Starch is hydrolysed by enzymes in the brush border of the intestinal mucosa."
"F"
"Starch is hydrolysed by amylase secreted in saliva and the pancreatic juice."
"The term 'resistant starch' is used to describe starch that is not hydrolysed by salivary and pancreatic amylase."
"T"
"Resistant starch leaves the small intestine undigested and is a substrate for bacterial fermentation in the large intestine."
54, glucox.bmp
"An alkaline copper reagent is specific for glucose in plasma or urine."
"F"
"Alkaline copper reagents will react with any reducing compound. In urine this will include reducing sugars other than glucose, including pentoses, and also ascorbic acid (vitamin C)."
"Glucose oxidase is specific for glucose in urine or plasma."
"T"
"Glucose oxidase will only react with glucose, so provides the basis of a specific test for glucose in plasma or urine."
55, blank.bmp
"The glycaemic index is a measure of the extent to which a carbohydrate has been digested."
"T"
"The glycaemic index is the increase in blood glucose after a test dose of a carbohydrate, compared with that after an equivalent amount of glucose. It therefore measures the extent of carbohydrate digestion and absorption."
"Carbohydrates with a low glycaemic index are slowly absorbed."
"T"
"The glycaemic index is the increase in blood glucose after a test dose of a carbohydrate, compared with that after an equivalent amount of glucose. It therefore measures the extent of carbohydrate digestion and absorption."
56, blank.bmp
"Disaccharides that are not hydrolysed in the small intestine are substrates for bacterial metabolism in the colon."
"T"
"This can lead to explosive watery diarrhoea after consumption of relatively large amounts of unabsorbable sugars."
"Sugar alcohols that are not absorbed in the small intestine are substrates for bacterial metabolism in the colon."
"T"
"This can lead to explosive watery diarrhoea after consumption of relatively large amounts of sugar alcohols."
57, blank.bmp
"The glycaemic index is the increase in blood glucose after a test dose of a carbohydrate compared with that after an equivalent amount of glucose."
"T"
"It therefore provides an index of the extent of digestion and absorption of the carbohydrate."
"The term 'resistant starch' is used to describe starch that has a glycaemic index >1."
"F"
"A glycaemic index > 1 is impossible, since the glycaemic index is the increase in blood sugar following a test dose of a carbohydrate compared with that after an equivalent amount of glucose. Resistant starch has a glycaemic index < 1, since it is (partially) resistant to amylase action."
58, glucox.bmp
"Glucose oxidase will give a false positive result for glucose in the presence of vitamin C."
"F"
"Vitamin C will reduce the oxidized dyestuff back to its colourless form, so the glucose oxidase assay will give a false negative result in the presence of vitamin C."
"Alkaline copper reagents will give a false positive result for glucose in the presence of vitamin C."
"T"
"Alkaline copper reagents will react with any reducing compound, and this includes vitamin C."
59, glucox.bmp
"Alkaline copper reagents will give a false negative result for glucose in the presence of vitamin C."
"F"
"Alkaline copper reagents will react with any reducing compound, and this includes vitamin C. They will give a false positive result in the presence of vitamin C."
"Alkaline copper reagents will give a false positive result for glucose in the presence of vitamin C."
"T"
"Alkaline copper reagents will react with any reducing compound, and this includes vitamin C. They will give a false positive result in the presence of vitamin C."
60, blank.bmp
"People who lack lactase suffer diarrhoea after consuming lactose because of the acidity of the products of bacterial metabolism of lactose."
"F"
"The problem is the osmotic effect of the products of bacterial fermentation, not the pH. Fermentation of lactate yields 4 mol lactic acid, accompanied by 4 mol of protons or sodium ions, so there is an 8-fold increase in osmolality."
"People who lack lactase suffer diarrhoea after consuming lactose because of the osmotic effect of the products of bacterial metabolism of lactose."
"T"
"The problem in people with alactasia is the osmotic effect of the products of bacterial fermentation. Fermentation of lactate yields 4 mol lactic acid, accompanied by 4 mol of protons or sodium ions, so there is an 8-fold increase in osmolality."
61, blank.bmp
"The glycaemic index of starch is always 1.0."
"F"
"The glycaemic index is the increase in blood glucose after a test dose of a carbohydrate compared with that after an equivalent amount of glucose. A value of 1 indicates complete digestion - a variable proportion of starch is resistant to amylase action, so the glycaemic index of starch will be < 1."
"The glycaemic index of starch is normally < 1.0."
"T"
"The glycaemic index is the increase in blood glucose after a test dose of a carbohydrate compared with that after an equivalent amount of glucose. A value of 1 indicates complete digestion - a variable proportion of starch is resistant to amylase action, so the glycaemic index of starch will be < 1."
62, glucox.bmp
"Alkaline copper reagents will give a false positive result for glucose in the presence of pentose sugars in urine."
"T"
"Alkaline copper reagents will react with any reducing compound, including pentose sugars in urine."
"Glucose oxidase will give a false positive result for glucose in the presence of pentose sugars in urine."
"F"
"Glucose oxidase is specific for glucose and will not react with any other sugars in plasma or urine."
63, blank.bmp
"A carbohydrate with a glycaemic index <1 is incompletely digested."
"T"
"The glycaemic index is the increase in blood glucose after a test dose of a carbohydrate, compared with that after an equivalent amount of glucose. A value < 1 indicates incomplete digestion."
"A carbohydrate with a glycaemic index >1 is incompletely digested."
"F"
"A glycaemic index > 1 is impossible, since the glycaemic index is the increase in blood sugar following a test dose of a carbohydrate compared with that after an equivalent amount of glucose, which is completely absorbed."
64, blank.bmp
"All dietary fibre is non-starch polysaccharide."
"F"
"A number of other compounds, including lignins, which are not polysaccharides, are included in the rather loose definition of dietary fibre."
"Non-starch polysaccharides may be either soluble or insoluble."
"T"
"Many of the non-starch polysaccharides are water-soluble and form viscous solutions, while others, like cellulose, are insoluble."
65, blank.bmp
"Soluble non-starch polysaccharides may be beneficial in treatment of diabetes mellitus because they increase the rate at which nutrients are absorbed from the gut."
"F"
"Quite the reverse - soluble non-starch polysaccharides increase the viscosity of gut contents, and slows the rate of nutrient absorption. This may be beneficial in the treatment of the early stages of maturity onset diabetes mellitus."
"Soluble non-starch polysaccharides may be beneficial in treatment of diabetes mellitus because they decrease the rate at which nutrients are absorbed from the gut."
"T"
"Soluble non-starch polysaccharides increase the viscosity of gut contents, and slows the rate of nutrient absorption. This may be beneficial in the treatment of the early stages of maturity onset diabetes mellitus."
66, blank.bmp
"Cellulose is hydrolysed by cellulase secreted in the pancreatic juice."
"F"
"Mammals do not secrete cellulase at all - it is an enzyme of some colonic bacteria and protozoa."
"Cellulose is a non-starch polysaccharide."
"T"
"Although cellulose is a polymer of glucose, the glucose units are linked by beta 1-4 glycoside bonds, and human beings do not have an enzyme that can hydrolyse these bonds. In starch the glucose units are linked by alpha 1-4 glucoside bonds."
67, blank.bmp
"Non-starch polysaccharides may provide protection against colo-rectal cancer because of the anti-proliferative action of some of the products of its metabolism by intestinal bacteria."
"T"
"Bacterial fermentation of nsp (and resistant starch) leads to production of a variety of short-chain fatty acids (e.g. butyrate) which may have anti-proliferative actions."
"Non-starch polysaccharides may provide protection against various cancers because they adsorb potential carcinogens in the diet."
"T"
"Carcinogens adsorbed onto non-starch polysaccharide cannot be absorbed."
68, blank.bmp
"A high intake of non-starch polysaccharide may be beneficial in treatment of diverticular disease of the colon."
"T"
"The increased bulk, and the water-retaining properties of non-starch polysaccharides, result in decreased intra-luminal pressure, and hence decreased risk of development of diverticula."
"A high intake of non-starch polysaccharide may be a factor in causing haemorrhoids."
"F"
"A high intake of nsp is probably protective against the development of haemorrhoids, since it leads to a softer faecal mass, and hence less straining to defecate."
69, blank.bmp
"Non-starch polysaccharides may lower blood cholesterol by binding bile acids in the gut lumen."
"T"
"If bile acids are bound by nsp in the gut lumen they will be lost in the faeces, rather than being re-absorbed for re-utilization. This means that more will have to be synthesized, thus depleting the body's cholesterol."
"Non-starch polysaccharides may increase blood cholesterol by binding bile acids in the gut lumen."
"F"
"If bile acids are bound by nsp in the gut lumen they will be lost in the faeces, rather than being re-absorbed for re-utilization. This means that more will have to be synthesized, thus depleting the body's cholesterol."
70, TAG.bmp
"Most triacylglycerols consist of three identical fatty acids esterified to glycerol.
"F"
"The three fatty acids esterified to glycerol are different from each other in most triacylglycerols."
"This compound is a phospholipid."
"F"
"This is a triacylglycerol."
71, cistrans.bmp
"Compound A is in the cis-configuration."
"T"
"In the cis-isomer the carbon chain continues on the same side of the double bond."
"Compound D is in the cis-configuration."
"F"
"In the cis-isomer the carbon chain continues on the same side of the double bond. This is a trans-isomer."
72, cistrans.bmp
"Compound C is in the cis-configuration."
"T"
"In the cis-isomer the carbon chain continues on the same side of the double bond."
"Compound B is in the cis-configuration."
"F"
"In the cis-isomer the carbon chain continues on the same side of the double bond. This is a trans-isomer."
73, cistrans.bmp
"Compound B is in the trans-configuration."
"T"
"In the trans-isomer the carbon chain continues on the opposite side of the double bond."
"Compound C is in the trans-configuration."
"F"
"In the trans-isomer the carbon chain continues on the opposite side of the double bond. This is a cis-isomer."
74, cistrans.bmp
"Compound D is in the trans-configuration."
"T"
"In the trans-isomer the carbon chain continues on the opposite side of the double bond."
"Compound A is in the trans-configuration."
"F"
"In the trans-isomer the carbon chain continues on the opposite side of the double bond. This is a cis-isomer."
75, cistrans.bmp
"In unsaturated fatty acids, the double bond is normally in the cis-configuration.
"T"
"Although there are small amounts of trans-unsaturated fatty acids in foods, most of the physiological unsaturated fatty acids have cis-double bonds."
"In unsaturated fatty acids, the double bond is normally in the trans-configuration.
"F"
"Although there are small amounts of trans-unsaturated fatty acids in foods, most of the physiological unsaturated fatty acids have cis-double bonds."
76, conjug.bmp
"Compound A has conjugated double bonds."
"F"
"The double bonds in compound A are methylene-interrupted, not conjugated."
"Compound A has methylene-interrupted double bonds."
"T"
"Compound has cis-cis methylene-interrupted double bonds. This is the usual arrangement in polyunsaturated fatty acids."
77, conjug.bmp
Compound B has methylene-interrupted double bonds."
"F"
"The double bonds in compound B are conjugated, not methylene-interrupted."
"Compound B has conjugated double bonds."
"T"
"The double bonds in compound B are conjugated, not methylene-interrupted."
78,blank.bmp
"Polyunsaturated fatty acids are precursors of prostaglandins."
"T"
"Long-chain polyunsaturated fatty acids are precursors for prostaglandin synthesis."
"Omega-3 polyunsaturated fatty acids can be used for synthesis of omega-6 polyunsaturated fatty acids.
"F"
"The omega-3 and omega-6 families of unsaturated fatty acid are not metabolically interconvertible; each gives rise to a different family of prostaglandins."
79, blank.bmp
"If a diet provides less than 40% of energy from fat, it is difficult to meet energy requirements.
"F"
"A diet providing about 30% of energy from fat is considered desirable - the western average is about 40%. It is only when fat provides less than about 10% of energy that it is difficult to meet energy requirements."
"If a diet provides less than 10% of energy from fat, it is difficult to meet energy requirements.
"T"
"A diet providing about 30% of energy from fat is considered desirable - the western average is about 40%. It is only when fat provides less than about 10% of energy that it is difficult to meet energy requirements."
80, blank.bmp
"Most triacylglycerols have an unsaturated fatty acid esterified to carbon-2 of glycerol.
"T"
"In most physiological triacylglycerols the fatty acid at carbon-2 is unsaturated - even in fats that are considered to be relatively highly saturated."
"There is an absolute requirement for fat in the diet, apart from the need for essential fatty acids.
"F"
"Apart from relatively small amounts of omega-3 and omega-6 polyunsaturated fatty acids there is no requirement for a dietary intake of fat. However, on a very low fat diet it is difficult to eat a large enough volume of food to meet energy requirements."
81, fatty.bmp
"In the human metabolism of unsaturated fatty acids, additional double bonds can only be introduced between the methyl group and the first existing double bond.
"F"
"Additional double bonds can only be introduced between the carboxyl group and the first existing double bond."
"In the human metabolism of unsaturated fatty acids, additional double bonds can only be introduced between the carboxyl group and the first existing double bond.
"T"
"Additional double bonds can only be introduced between the carboxyl group and the first existing double bond."
82, fatty.bmp
"The saturated fatty acid stearate (C18:0) can readily be desaturated to yield oleate (C18:1 n-9), so there is no requirement for a dietary intake of omega-9 fatty acids."
"T"
"There is a requirement for omega-3 and omega-6 unsaturated fatty acids, but the human desaturase can indeed introduce a double bond at carbon-9 to permit synthesis of C18:1 n-9 from C18:0."
"Human tissues have a desaturase, so there is no dietary requirement for unsaturated fatty acids."
"F"
"The human desaturase can introduce a double bond at carbon-9 to permit synthesis of C18:1 n-9 from C18:0, or to insert additional double bonds between an existing n-3 or n-6 double bond and the carboxyl group. However it cannot introduce a double bond in position omega-3 or omega-6. There is therefore a requirement for a dietary intake of both omega-3 and omega-6 fatty acids."
83, fatty2.bmp
"High intakes of saturated fatty acids may increase serum cholesterol.
"T"
"By contrast, relatively high intakes of unsaturated fatty acids have a cholesterol-lowering action."
"High intakes of unsaturated fatty acids may increase serum cholesterol.
"F"
"Unsaturated fatty acids have a cholesterol-lowering action; it is saturated fatty acids that increase serum cholesterol."
84, fatty2.bmp
"The three families of unsaturated fatty acids (omega-3, omega-6 and omega-9) can be interconverted in the body.
"F"
"Because additional double bonds can only be introduced between the carboxyl group and the first existing double bond, the three families of fatty acids (omega-3, omega-6 and omega-9) are not metabolically interconvertible."
"The three families of unsaturated fatty acids (omega-3, omega-6 and omega-9) cannot be interconverted in the body.
"T"
"Because additional double bonds can only be introduced between the carboxyl group and the first existing double bond, the three families of fatty acids (omega-3, omega-6 and omega-9) are not metabolically interconvertible."
85, blank.bmp
"The main importance of phospholipids in membrane structure is that they can be hydrolysed to yield inositol trisphosphate.
"F"
"While formation of inositol trisphosphate is important in transmembrane signalling, the main importance of phospholipids in membranes is that they form the lipid bilayer, with hydrophilic faces and a hydrophobic interior."
"Triacylglycerols are insoluble in water, but can be emulsified by phospholipids."
"T"
"Phospholipids have both hydrophobic and hydrophilic regions, so they act as very effective emulsifying agents."
86, fatty2.bmp
"Both omega-3 and omega-6 polyunsaturated fatty acids can undergo elongation and further unsaturation in the body.
"T"
"But additional double bonds can only be introduced between the carboxyl group and the nearest existing double bond, so that interconversion of the omega-3, omega-6 and omega-9 families of fatty acids is not possible."
"Omega-3 and omega-6 fatty acids cannot undergo elongation and further unsaturation in the body."
"F"
"The human desaturase can introduce additional double bonds between the carboxyl group and the nearest existing double bond, so that interconversion omega-3 and omega-6 fatty acids can indeed undergo elongation and further desaturation. However, interconversion of the omega-3, omega-6 and omega-9 families of fatty acids is not possible."
87, blank.bmp
"Fat in the diet makes chewing and swallowing food considerably more difficult."
"F"
"Fat aids chewing and swallowing of food, as well as carrying much of the flavour and aroma."
"Fat carries much of the flavour of some foods."
"T"
"Fat aids chewing and swallowing of food, as well as carrying much of the flavour and aroma."
88, fatty2.bmp
"Omega-9 unsaturated fatty acids can be used for synthesis of the omega-3 series, but not the omega-6 series, of polyunsaturated fatty acids.
"F"
"Because additional double bonds can only be introduced between the carboxyl group and the first existing double bond, the three families of fatty acids (omega-3, omega-6 and omega-9) are not metabolically interconvertible."
"Omega-9 unsaturated fatty acids can be used for synthesis of the omega-6 series, but not the omega-3 series, of polyunsaturated fatty acids.
"F"
"Because additional double bonds can only be introduced between the carboxyl group and the first existing double bond, the three families of fatty acids (omega-3, omega-6 and omega-9) are not metabolically interconvertible."
89, blank.bmp
"Fat is desirable in the diet to permit absorption of vitamins A and E.
"T"
"The fat-soluble vitamins (A, D, E and K), and the carotenoids, can only be absorbed dissolved in dietary fat."
"On a very low-fat diet it is likely that vitamin A deficiency will develop."
"T"
"The fat-soluble vitamins (A, D, E and K), and the carotenoids, can only be absorbed dissolved in dietary fat."
90, TAG.bmp
"Diacylglycerols consist of two fatty acids esterified to glycerol.
"T"
"Lipase catalyses hydrolysis of the fatty acids esterified to carbons 1 and 3 of glycerol in a triacylglycerol, so removal of one fatty acid will result in formation of a 1,2-diacylglycerol, with a free hydroxyl group on carbon-3 of glycerol."
"Monoacylglycerols consist of two fatty acids esterified to glycerol."
"F"
"Lipase catalyses hydrolysis of the fatty acids esterified to carbons 1 and 3 of glycerol in a triacylglycerol, so removal of one fatty acid will result in formation of a 1,2-diacylglycerol, with a free hydroxyl group on carbon-3 of glycerol. The next step is removal of another fatty acid, resulting a 2-monoacylglycerol, with just one fatty acid esterified to carbon-2 of the glycerol."
91, blank.bmp
"In phospholipids there is a phospho-diester linkage between glycerol and a hydrophilic group.
"T"
"The phosphate is esterified to both glycerol and the hydrophilic group; this is therefore, by definition, a phospho-diester linkage."
"Triacylglycerols are hydrophilic.
"F"
"Triacylglycerols are extremely hydrophobic."
92, TAG.bmp
"This compound is a phospholipid.
"F"
"This is a triacylglycerol."
"This compound is insoluble in water.
"T"
"Triacylglycerols are extremely hydrophobic, and therefore insoluble in water."
93, TAG.bmp
"This compound may be hydrolysed by lipase to yield free (non-esterified) fatty acids and a mono-acylglycerol.
"T"
"Lipase catalyses hydrolysis of the fatty acids esterified to carbons 1 and 3 of glycerol in a triacylglycerol, so removal of two fatty acid will result in formation of a 2-mono-acylglycerol, with free hydroxyl groups on carbons 1 and 3 of glycerol."
"This compound is an important component of cell membranes."
"F"
"Thus is a triacylglycerol; they are the major storage lipid in the body, but are unimportant in cell membrane structure, where it is phospholipids that are important."
94, fatty.bmp
"Compound A is a polyunsaturated fatty acid."
"F"
"Compound A has no double bonds - it is a saturated fatty acid."
"Compound B is a polyunsaturated fatty acid."
"F"
"Compound B has only one double bond - it is a mono-unsaturated fatty acid."
95, fatty.bmp
"Compound A is a mono-unsaturated fatty acid."
"F"
"Compound A has no double bonds - it is a saturated fatty acid."
"Compound C is a polyunsaturated fatty acid."
"T"
"Compound C has two double bonds - it is therefore a polyunsaturated fatty acid."
96, fatty.bmp
"The double bonds in compounds B and C are in the trans-conformation."
"F"
"These are cis-isomers - the carbon chain continues on the same side of the double bond. In a trans-isomer it continues on the opposite side."
"The double bonds in compounds B and C are in the cis-conformation."
"T"
"These are cis-isomers - the carbon chain continues on the same side of the double bond. In a trans-isomer it continues on the opposite side."
97, fatty2.bmp
"Compound C is an omega-6 unsaturated fatty acid."
"T"
"The first double bond is at carbon-6 from the methyl end, so this is indeed an omega-6 unsaturated fatty acid."
"Compound C is an omega-3 unsaturated fatty acid."
"F"
"The first double bond is at carbon-6 from the methyl end, so this is an omega-6 unsaturated fatty acid."
98, fatty2.bmp
"Compound B is an omega-6 unsaturated fatty acid."
"F"
"The first double bond is at carbon-9 from the methyl end, so this is an omega-9 unsaturated fatty acid."
"Compound B is an omega-3 unsaturated fatty acid."
"F"
"The first double bond is at carbon-9 from the methyl end, so this is an omega-9 unsaturated fatty acid."
99, fatty2.bmp
"Compound B can readily be synthesized from compound A in the body."
"T"
"Compound B is an omega-9 unsaturated fatty acid, and the human desaturase can introduce a double bond in this position in C18:0 (which is compound A)."
"Compound C can readily be synthesized from compound A in the body."
"F"
"Compound C is an omega-6 unsaturated fatty acid, and the human desaturase cannot introduce a double bond in this position in C18:0 (which is compound A)."
100, fatty2.bmp
"Compound C can readily be synthesized from compound B in the body."
"F"
"Compound C is an omega-6 unsaturated fatty acid, and the human desaturase cannot introduce a double bond in this position in C18:1 n-9 (which is compound B)."
"Compound D can readily be synthesized from compound C in the body."
"F"
"Compound D is an omega-3 unsaturated fatty acid, and the human desaturase cannot introduce a double bond in this position in C18:2 n-6 (which is compound C)."
101, fatty2.bmp
"Compound A is C18:1 n-9."
"F"
"Compound A has no double bonds - it is C18:0."
"Compound A is C18:0."
"T"
"Compound A has no double bonds - it is C18:0."
102, fatty2.bmp
"Compound B is C18:1 n-9."
"T"
"Compound B has one double bond, at carbon-9 from the methyl end - it is indeed C18:1 n-9."
"Compound B is C18:1 n-6."
"F"
"Compound B has one double bond, at carbon-9 from the methyl end - it is C18:1 n-9."
103, fatty2.bmp
"Compound C is C18:2 n-6."
"T"
"Compound C has two bonds, and the first is at carbon-6 from the methyl end - it is indeed C18:2 n-6."
"Compound C is C18:6 n-2."
"F"
"Compound C has two bonds, and the first is at carbon-6 from the methyl end - it is indeed C18:2 n-6."
104, fatty2.bmp
"Compound D is C18:3 n-3."
"T"
"Compound D has three double bonds, and the first is at carbon-3 from the methyl end - it is indeed C18:3 n-3."
"Compound D is C18:3 n-6."
"F"
"Compound D has three double bonds, and the first is at carbon-3 from the methyl end - it is C18:3 n-3."
105, fatty2.bmp
"The double bonds in these fatty acids are conjugated."
"F"
"Conjugated means that there are alternating single and double bonds. The double bonds here are separated by a methylene bridge. Although conjugated polyunsaturated fatty acids do occur, they are rare, and all of the important polyunsaturated fatty acids are methylene-interrupted."
"The double bonds in these fatty acids are methylene-interrupted."
"T"
"The double bonds here are separated by a methylene bridge. Although conjugated polyunsaturated fatty acids do occur, they are rare, and all of the important polyunsaturated fatty acids are methylene-interrupted."
106, blank.bmp
"The fatty acid which is abbreviated to C16:0 will have no double bonds.
"T"
"The number after the colon in the shorthand indicates the number of double bonds in the fatty acid. :0 means a saturated fatty acid with no double bonds."
"The fatty acid which is abbreviated to C18:3 n-6 will have 6 double bonds.
"F"
"The number after the colon in the shorthand indicates the number of double bonds in the fatty acid. :3 means a fatty acid with 3 double bonds. n-6 shows that the first double bond is at carbon-6 from the methyl end."
107, blank.bmp
"The fatty acid which is abbreviated to C18:1 n-6 is a mono-unsaturated fatty acid."
"T"
"The number after the colon in the shorthand indicates the number of double bonds in the fatty acid. :1 means a fatty acid with 1 double bond. n-6 shows that the first double bond is at carbon-6 from the methyl end."
"The fatty acid which is abbreviated to C22:6 n-3 has six double bonds.
"T"
"The number after the colon in the shorthand indicates the number of double bonds in the fatty acid. :6 means a fatty acid with 6 double bonds. n-3 shows that the first double bond is at carbon-6 from the methyl end."
108, blank.bmp
"In the fatty acid that is abbreviated to C18:2 n-6 the first double bond is between carbons 6 and 7 from the carboxyl group."
"F"
"The n- (or omega) notation means that carbon atoms are counted from the methyl group, while in systematic chemical nomenclature the carbon atoms are numbered from the one that is the functional group for which the compound is named - in this case the carboxyl group."
"In the fatty acid that is abbreviated to C18:2 n-3 the first double bond is between carbons 3 and 4 from the carboxyl group."
"F"
"The n- (or omega) notation means that carbon atoms are counted from the methyl group, while in systematic chemical nomenclature the carbon atoms are numbered from the one that is the functional group for which the compound is named - in this case the carboxyl group."
109, blank.bmp
"In the fatty acid that is abbreviated to C22:6 n-9 the double bond is between carbons 9 and 10 from the carboxyl group.
"F"
"The n- (or omega) notation means that carbon atoms are counted from the methyl group, while in systematic chemical nomenclature the carbon atoms are numbered from the one that is the functional group for which the compound is named - in this case the carboxyl group."
"In the fatty acid that is abbreviated to C22:6 n-3 the double bond is between carbons 3 and 4 from the carboxyl group.
"F"
"The n- (or omega) notation means that carbon atoms are counted from the methyl group, while in systematic chemical nomenclature the carbon atoms are numbered from the one that is the functional group for which the compound is named - in this case the carboxyl group."
110, blank.bmp
"The fatty acid abbreviated to C24:0 is a polyunsaturated fatty acid."
"F"
"There are no double bonds in C24:0 - it is a saturated fatty acid."
"The fatty acid abbreviated to C16:1 n-6 has six double bonds.
"F"
"There will be 1 double bond in C16:1 n-6. The n-6 means that the first double bond will be at carbon 6 from the methyl group."
111, blank.bmp
"The fatty acid abbreviated to C18:3 n-3 may be a precursor of C22:6 n-3 in the body.
"T"
"Both chain elongation and desaturation to introduce double bonds between an existing double bond and the carboxyl group occur readily, so C18:3 n-3 may indeed be a precursor of C22:6 n-3 in the body."
"The fatty acid abbreviated to C18:2 n-6 may be a precursor of C22:6 n-6 in the body.
"T"
"Both chain elongation and desaturation to introduce double bonds between an existing double bond and the carboxyl group occur readily, so C18:2 n-6 may indeed be a precursor of C22:6 n-6 in the body."
112, blank.bmp
"No fatty acids are dietary essentials because there are enzymes in human tissues that will catalyse elongation and desaturation of fatty acids."
"F"
"Although C18:0 is readily desaturated to yield C18:1 n-9, there is no way in which C18 n-3 or n-6 fatty acids can be synthesized from saturated precursors. There is a dietary requirement for omega-3 and omega-6 fatty acids. Longer-chain omega-3 and omega-6 fatty acids can be synthesized from appropriate unsaturated C18 precursors."
"Human enzymes cannot catalyse the insertion of double bonds between the carboxyl group of an unsaturated fatty acid and an existing double bond.
"F"
"The human desaturase can only insert double bonds between an existing double bond and the carboxyl group of an unsaturated fatty acid."
113, blank.bmp
"Human enzymes cannot catalyse the insertion of double bonds between the terminal methyl group of an unsaturated fatty acid and an existing double bond."
"T"
"The human desaturase can only insert double bonds between an existing double bond at the carboxyl group of an unsaturated fatty acid."
"Human enzymes can catalyse the insertion of double bonds between the terminal methyl group of an unsaturated fatty acid and an existing double bond."
"F"
"The human desaturase can only insert double bonds between an existing double bond at the carboxyl group of an unsaturated fatty acid."
114, blank.bmp
"Lipase secreted by the tongue is important in the hydrolysis of triacylglycerols."
"T"
"A significant amount of lipase is secreted by the tongue, and this lingual lipase is indeed important in triacylglycerol hydrolysis - as is the lipase secreted by the gastric mucosa."
"Pancreatic lipase catalyses complete hydrolysis of triacylglycerols to free fatty acids and glycerol."
"F"
"Pancreatic lipase only catalyses the hydrolysis of fatty acids esterified to carbons-1 and -3 of glycerol, leaving 2-monoacylglycerol as the product."
115, micelle.bmp
"The free fatty acids and mono- and diacylglycerols formed by lipase action emulsify the lipid micelles in the intestinal mucosa."
"T"
"Both free fatty acids and mono- and diacylglycerols are amphiphilic (i.e. they have both hydrophobic and hydrophilic regions in the same molecule) and hence they can, and do, act as emulsifying agents. The bile salts also act as emulsifying agents to form lipid micelles that are small enough to be absorbed."
"The bile salts emulsify the lipid micelles in the intestinal mucosa."
"T"
"The bile salts, together with free fatty acids and mono- and diacylglycerols formed by lipase action, act as emulsifying agents to form lipid micelles that are small enough to be absorbed."
116, TAG.bmp
"Patients with pancreatic insufficiency are more or less completely unable to digest triacylglycerols because of lack of pancreatic lipase."
"F"
"Lingual and gastric lipases can achieve about 50% hydrolysis of triacyglycerols to fatty acids and monoacylglycerol."
"Patients with pancreatic insufficiency can digest triacylglycerols to a considerable extent despite their lack of pancreatic lipase."
"T"
"Lingual and gastric lipases can achieve about 50% hydrolysis of triacyglycerols to fatty acids and monoacylglycerol."
117, TAG.bmp
"Lipases catalyse hydrolysis of the fatty acids esterified at carbons 1 and 3 of glycerol."
"T"
"The end-product of lipase action is 2-monoacylglycerol."
"Monoacylglycerols have a fatty acid esterified at carbon-3 of glycerol."
"F"
"The secreted lipases catalyse the hydrolysis of fatty acids esterified to carbons-1 and -3 of glycerol, leaving 2-monoacylglycerol as the product - i.e. the fatty is esterified to carbon-2 of glycerol."
118, TAG.bmp
"2-Monoacylglycerols are hydrolysed to free fatty acids and glycerol by pancreatic esterase."
"T"
"The secreted lipases catalyse the hydrolysis of fatty acids esterified to carbons-1 and -3 of glycerol, leaving 2-monoacylglycerol as the product - i.e. the fatty is esterified to carbon-2 of glycerol. Pancreatic esterase then hydrolyses the ester to carbon-2 of glycerol."
"2-Monoacylglycerols are hydrolysed to free fatty acids and glycerol by pancreatic esterase."
"F"
"The secreted lipases catalyse the hydrolysis of fatty acids esterified to carbons-1 and -3 of glycerol, leaving 2-monoacylglycerol as the product - i.e. the fatty is esterified to carbon-2 of glycerol. Pancreatic esterase then hydrolyses the ester to carbon-2 of glycerol."
119, micelle.bmp
"Cholesterol and fat-soluble vitamins are absorbed after conjugation catalysed by pancreatic lipase."
"F"
"Lipase catalyses hydrolysis of fatty acid esters, not conjugation reactions. Cholesterol and fat-soluble vitamins are dissolved in the hydrophobic interior of the lipid micelles. This means that on a very low fat diet there may be problems in absorbing the fat-soluble vitamins."
"Cholesterol and fat-soluble vitamins are absorbed dissolved in the hydrophobic core of the lipid micelle."
"T"
"Cholesterol and fat-soluble vitamins are dissolved in the hydrophobic interior of the lipid micelles. This means that on a very low fat diet there may be problems in absorbing the fat-soluble vitamins."
120, TAG.bmp
"Lipase secreted by the gastric mucosa is important in hydrolysis of triacylglycerols.
"T"
"The combined action of lingual and gastric lipases results in hydrolysis of up to 50% of dietary triacylglycerol to monoacylglycerol and free fatty acids. The importance of this is that patients with severe pancreatic insufficiency (who therefore secrete little or no pancreatic lipase) are still able to hydrolyse, and hence tolerate, a significant amount of fat in the diet."
"Lingual lipase (secreted by the tongue) catalyses complete hydrolysis of triacylglycerols to free fatty acids and glycerol.
"F"
"Lingual lipase, like other secreted lipases, only catalyses the hydrolysis of fatty acids esterified to carbons-1 and -3 of glycerol, leaving 2-monoacylglycerol as the product."
121, micelle.bmp
"Phospholipids help to emulsify the lipid micelles in the intestinal lumen."
"T"
"Phospholipids are amphiphilic (i.e. they have both hydrophobic and hydrophilic regions in the same molecule) and hence they can, and do, act as emulsifying agents. Obviously, since phospholipids are an essential part of all cell membranes, there will be significant amounts in foods. Although some will be hydrolysed by intestinal phospholipase, some will remain to act as an emulsifying agent."
"Bile salts help to emulsify the lipid micelles in the intestinal mucosa."
"T"
"Bile salts are amphiphilic (i.e. they have both hydrophobic and hydrophilic regions in the same molecule) and hence they can, and do, act as emulsifying agents."
122, micelle.bmp
"Dietary cholesterol helps to emulsify the lipid micelles in the intestinal lumen."
"F"
"Cholesterol is a very hydrophobic compound - it cannot possible help in emulsification of lipid micelles. It is dissolved in the hydrophobic core of the micelle."
"Free fatty acids formed by the action of lipases and esterase help to emulsify the lipid micelles in the intestinal lumen."
"T"
"Fatty acids are amphiphilic (i.e. they have both hydrophobic and hydrophilic regions in the same molecule) and hence they can, and do, act as emulsifying agents."
123, blank.bmp
"Free (non-esterified) fatty acids absorbed from the small intestine enter the portal circulation and are transported bound to serum albumin."
"F"
"The free (non-esterified) fatty acids that circulate bound to albumin arise as a result of lipase action in adipose and other tissues. There is no transfer of free fatty acids from the intestinal mucosa into the bloodstream."
"Fatty acids absorbed from the gut are re-esterified to triacylglycerol in the small intestinal mucosa."
"T"
"Triacylglycerol synthesized in the intestinal mucosa from dietary lipids enters the lymphatic circulation in chylomicrons."
124, blank.bmp
"Triacylglycerol synthesized in the intestinal mucosa from dietary lipids enters the lymphatic circulation in chylomicrons."
"T"
"The intestinal mucosa esterifies fatty acids to form triacylglycerol, then packages them with proteins to form chylomicrons that enter the lymphatic circulation."
"Triacylglycerol synthesized in the intestinal mucosa from dietary lipids enters the hepatic portal circulation in chylomicrons."
"F"
"The intestinal mucosa esterifies fatty acids to form triacylglycerol, then packages them with proteins to form chylomicrons that enter the lymphatic circulation, not the hepatic portal vein."
125, blank.bmp
"Bile salt conjugates are formed by intestinal bacterial action."
"F"
"The bile salt conjugates with glycine and taurine are formed in the liver. Intestinal bacteria hydrolyse conjugates to liberate free bile salts."
"Intestinal bacteria metabolize bile salts to compounds that are absorbed and resecreted in the bile."
"T"
"The secondary bile salts are the result of intestinal bacterial action, and they are indeed absorbed, stored in the gallbladder and resecreted."
126, blank.bmp
"After a high-fat meal, plasma appears milky due to the presence of chylomicrons."
"T"
"Chylomicrons are the largest of the plasma lipoproteins - so large that they scatter light, so chylomicron-rich plasma has a milky appearance."
"Chylomicrons consist mainly of triacylglycerol surrounded by proteins synthesized mainly in the small intestinal mucosa."
"T"
"The intestinal mucosa esterifies fatty acids to form triacylglycerol, then packages them with proteins to form chylomicrons that enter the lymphatic circulation, then the bloodstream at the thoracic duct."
127, blank.bmp
"Free fatty acids absorbed from the small intestine enter the lymphatic circulation."
"F"
"Fatty acids absorbed from the small intestine are esterified to triacylglycerol and assembled into chylomicrons before entering the lymphatic circulation."
"The products of fat absorption enter the peripheral circulation without passing through the liver."
"T"
"Chylomicrons, containing the products of lipid absorption, enter the lymphatic circulation, which drains into the bloodstream at the thoracic duct. This means that chylomicrons circulate to all peripheral tissues before the chylomicron remnants reach the liver, unlike material that is absorbed into the hepatic portal system."
128, blank.bmp
"Bile salts are synthesized in the gall bladder."
"F"
"Bile salts are stored in the gall bladder ready for secretion. They are synthesized in the liver - and note that there is significant reabsorption of bile salts, with recycling through the liver - of some 30 g of bile salt conjugates secreted each day, only 1 - 2 g are excreted in the faeces."
"Drugs that bind bile salts in the intestinal lumen can be used to lower serum cholesterol."
"T"
"Bile salts are synthesized in the liver from cholesterol, and there is significant reabsorption of bile salts, with recycling through the liver - of some 30 g of bile salt conjugates secreted each day, only 1 - 2 g are excreted in the faeces. If faecal excretion is increased, more will have to be synthesized from cholesterol."
129, blank.bmp
"Bile salts are synthesized from cholesterol in the liver."
"T"
"Because there is significant reabsorption and re-utilisation of bile salts (of some 30 g of bile salt conjugates secreted each day, only 1 - 2 g are excreted in the faeces), increasing the faecal excretion of bile salts -(e.g. by binding to non-starch polysaccharide) can be useful in increasing the utilisation of cholesterol, and can have a useful hypocholesterolaemic action."
"Dietary cholesterol is essential for the synthesis of bile salts in the liver.
"F"
"Cholesterol is not a dietary essential - there is considerable endogenous synthesis of cholesterol in the liver and other tissues. Indeed, it is a failure to regulate endogenous cholesterol synthesis, rather than an excessive dietary intake, that is the main problem in hypercholesterolaemia."
130, micelle.bmp
"Lipid micelles contain free fatty acids, monoacylglycerol and phospholipids."
"T"
"As well as some intact triacylglycerol, plus fat-soluble vitamins, cholesterol and bile salts."
"Lipid micelles contain intact triacylglycerol, plus fat-soluble vitamins, cholesterol and bile salts."
"T"
" As well as free fatty acids, monoacylglycerol and phospholipids."
131, blank.bmp
"Chylomicrons consist of triacylglycerol emulsified with bile salts."
"F"
"Chylomicrons consist of triacylglycerol and other lipids surrounded by protein which renders them soluble in plasma. It is micelles that consist of triacylglycerol emulsified with bile salts."
"Triacylglycerol synthesized in the intestinal mucosa enters the portal circulation in very low-density lipoprotein (VLDL)."
"F"
"Dietary lipids enter the lymphatic circulation in chylomicrons assembled in the intestinal mucosa. VLDL are assembled in, and exported by, the liver."
132, blank.bmp
"Chylomicrons are lipoproteins."
"T"
"They consist of a hydrophobic core of lipid, surrounded by a coat of protein that emulsifies them in the plasma. Chylomicrons are the largest of the plasma lipoproteins."
"Part of the increased metabolic rate after a meal can be accounted for by the energy cost of synthesising triacylglycerol in the intestinal mucosa."
"T"
"Fatty acids are esterified to triacylglycerol before the assembly of chylomicrons - at a cost of 6 or 7 ATP per mol of triacylglycerol formed."
133, blank.bmp
"Bile salts are essential for the action of pancreatic lipase."
"F"
"The bile salts actually inhibit pancreatic lipase. Their importance is in the final emulsification of micelles into droplets small enough to enter mucosal cells."
"The bile salts are secreted as conjugates with glycine or taurine."
"T"
"This conjugation renders the hydrophilic region of the molecules very much more hydrophilic, so enhancing their detergent effect / emulsifying action very considerably."
134, blank.bmp
"Diet is the main source of cholesterol in the lumen of the small intestine."
"F"
"About four times more cholesterol is secreted in the bile each day than the dietary intake."
"Free bile salts are formed in the small intestine by the action of lipase on the conjugates."
"F"
"Lipase does not act on bile salt conjugates. It is intestinal bacterial action that results in hydrolysis of the bile salt conjugates."
135, blank.bmp
"Binding of bile salts to non-starch polysaccharide in the gut will lead to increased bacterial metabolism and hence increased reabsorption."
"F"
"If the bile salts are bound to non-starch polysaccharide then they will be unavailable for either bacterial action or re-absorption. Binding will lead to increased loss in faeces, and hence an increased requirement for synthesis of bile salts from cholesterol. This may be important in lowering the body burden of cholesterol. The treatment of severe hypercholesterolaemia commonly involves feeding ion exchange resins that bind relatively large amounts of bile salts in the gut lumen."
"The secondary bile salts are formed by intestinal bacterial metabolism."
"T"
"They are then absorbed, conjugated in the liver and stored in the gall bladder for secretion."
136, blank.bmp
"Considerably more cholesterol is secreted in the bile each day than is taken in from the diet."
"T"
"Average dietary intake of cholesterol is around 500 mg /day, while as much as 2 g of cholesterol may be secreted in the bile each day - and mostly re-absorbed."
"The products of bacterial metabolism of the bile salts are almost completely excreted in the faeces."
"F"
"Most of the bile salts, both the primary bile salts synthesized in the liver and the secondary bile salts resulting from bacterial action, are re-absorbed. Faecal excretion is less than 5% of the total amount secreted each day."
137, blank.bmp
"The bile salts are inhibitors of pancreatic lipase."
"T"
"The bile salts inhibit pancreatic lipase. Their importance is in the final emulsification of micelles into droplets small enough to enter mucosal cells."
"The products of bacterial metabolism of the bile salts are mainly reabsorbed and conjugated for excretion in the urine."
"F"
"The secondary bile salts formed by bacterial action are reabsorbed, and conjugated - for resecretion in the bile."
138, blank.bmp
"Gall stones are due to crystallization of cholesterol in the bile."
"T"
"Even under normal conditions the ratio of cholesterol (a very hydrophobic compound) : bile salts plus phospholipids (both amphiphilic compounds) in the bile is close to the point at which cholesterol begins to crystallize. It requires only a relatively small increase in the concentration of cholesterol in the bile for it to crystallize in the gall bladder, leading to gall stones."
"Gall stones are very much more common in people who are overweight or obese."
"T"
"The risk of developing gall stones is 4 - 5-times higher in obese people than lean people."
139, blank.bmp
"Denaturation of a protein is important for digestion."
"T"
"Native proteins are resistant to the action of proteolytic enzymes; opening up the structure of the protein exposes more susceptible peptide bonds for hydrolysis."
"Native proteins are relatively resistant to digestion."
"T"
"Native proteins are resistant to the action of proteolytic enzymes; opening up the structure of the protein exposes more susceptible peptide bonds for hydrolysis."
140, blank.bmp
"Disulphide bonds are important in the primary structure of many proteins."
"F"
"The primary structure is the sequence of amino acids in the peptide chain. Disulphide bridges are important in tertiary structure."
"Side-chain peptide bonds between lysine and glutamate or aspartate are important in the primary structure of many proteins."
"F"
"The primary structure is the sequence of amino acids in the peptide chain, linked by peptide bonds between the alpha-carbons of amino acids. Side-chain peptide bonds are important in tertiary structure."
141, peptide.bmp
"Reaction A is a hydrolysis."
"F"
"Reaction A is a condensation reaction, with the elimination of water, not hydrolysis (which is the cleavage of a bond by addition of water)."
"Reaction A is a condensation reaction."
"T"
"Reaction A is a condensation reaction, with the elimination of water."
142, peptide.bmp
"Reaction B is a hydrolysis."
"T"
"Reaction B is the cleavage of a peptide bond by water - this is hydrolysis."
"Reaction A is a condensation reaction."
"F"
"Reaction B is the cleavage of a peptide bond by water - this is hydrolysis, not a condensation reaction.."
143, peptide.bmp
"The bond in region C is an ester bond."
"F"
"This is a peptide bond, between the amino group of one amino acid and the carboxyl group of another."
"The bond in region C is a peptide bond."
"T"
"This is a peptide bond, between the amino group of one amino acid and the carboxyl group of another."
144, blank.bmp
"Denaturation of a protein is the result of breaking the hydrogen bonds that stabilize the secondary structure."
"T"
"The secondary structure of proteins is stabilized by hydrogen bonds. Native proteins are resistant to the action of proteolytic enzymes; opening up the structure of the protein exposes more susceptible peptide bonds for hydrolysis. This means that denaturation is important for the digestion of proteins."
"Denaturation of a protein is the result of breaking the peptide bonds."
"F"
"Denaturation does not affect the (covalent) peptide bonds in a protein - denaturation it is the result of disruption of the hydrogen bonds that stabilizer secondary structure."
145, blank.bmp
"The alpha-helix is a type of secondary structure of proteins."
"T"
"The alpha-helix is one of the two main types of secondary structure of proteins - the ways in which different regions of the linear sequence of amino acids that is the primary sequence of the protein chain fold."
"The alpha-helix is maintained by hydrogen bonds between peptide bonds in the polypeptide chain."
"T"
"In the alpha helix hydrogen bonds are formed between amino acids in the same region of the peptide chain, so causing the chain to coil up into a helix."
146, blank.bmp
"In the alpha-helix hydrogen bonds are formed between amino acids in the same region of the peptide chain, so causing the chain to coil up into a helix."
"T"
"The alpha-helix is one of the two main types of secondary structure of proteins; hydrogen bonds are formed between peptide bonds in the same region of the peptide chain."
"In the alpha helix hydrogen bonds are formed between amino acids in two different regions of the peptide chain, so causing the chain to coil up into a helix."
"F"
"In the alpha-helix the hydrogen bonds are formed between peptide bonds in the same region of the peptide chain."
147, blank.bmp
"In beta-pleated sheet protein structure, hydrogen bonds are formed between amino acids in the same region of the peptide chain."
"F"
"Beta-pleated sheet is one of the two main types of secondary structure of proteins; hydrogen bonds are formed between different regions of the polypeptide chain that lie alongside each other."
"In beta-pleated sheet protein structure hydrogen bonds are formed between different regions of the polypeptide chain that lie alongside each other."
"T"
"Beta-pleated sheet is one of the two main types of secondary structure of proteins; hydrogen bonds are formed between different regions of the polypeptide chain that lie alongside each other - the polypeptide chains may be parallel or antiparallel."
148, blank.bmp
"In the alpha-helix the peptide chains may be either parallel or anti-parallel."
"F"
"There is only one peptide chain involved in the alpha-helix."
"In the beta-pleated sheet protein structure the peptide chains may be either parallel or anti-parallel."
"T"
"Beta-pleated sheet is one of the two main types of secondary structure of proteins; hydrogen bonds are formed between different regions of the polypeptide chain that lie alongside each other - the chains may run in the same (parallel) or opposite (anti-parallel) directions."
149, blank.bmp
"The double helix is an example of secondary structure of a protein."
"F"
"The double helix is the structure of DNA - it is the alpha-helix that is a type of protein secondary structure."
"The double helix is an example of secondary structure of a protein."
"F"
"The double helix is the structure of DNA - it is the alpha-helix that is a type of protein secondary structure."
150, blank.bmp
"The higher orders of structure in a protein molecule are the natural consequence of the primary structure."
"T"
"The way in which a protein folds into secondary and higher levels of structure is determined by the sequence of amino acids - the primary structure of the protein."
"Although different proteins have different primary sequences, they all have the same secondary structure."
"F"
"The way in which a protein folds into secondary and higher levels of structure is determined by the sequence of amino acids - the primary structure of the protein."
151, blank.bmp
"All proteins have the same primary structure."
"F"
"The primary structure of a protein is its sequence of amino acids. This is always the same for the same protein, but differs from one protein to another."
"The primary structure of any one protein is always the same."
"T"
"The primary structure of a protein is its sequence of amino acids. This is always the same for the same protein, and is determined by the gene coding for that protein, but differs from one protein to another."
152, blank.bmp
"The primary structure of a polypeptide is a random arrangement of amino acids."
"F"
"In any one protein the primary structure is always the same; the sequence of amino acids is determined by the DNA coding for that protein."
"The primary structure of any one protein is always the same."
"T"
"The primary structure of a protein is its sequence of amino acids. This is always the same for the same protein, and is determined by the gene coding for that protein, but differs from one protein to another."
153, blank.bmp
"The secondary structure of proteins is the result of hydrogen bonding between the -CO and -NH groups in the backbone of the polypeptide chain."
"T"
"Hydrogen bonds between the peptide bonds stabilize the secondary structure of proteins."
"The secondary structure of proteins is the result of hydrogen bonding between side chains oif the amnino acids in the polypeptide chain."
"F"
"The secondary structure of proteins is the result of hydrogen bonding between the -CO and -NH groups in the backbone of the polypeptide chain."
154, blank.bmp
"The tertiary structure of proteins is the aggregation of polypeptide chains to form biologically active molecules with allosteric properties."
"F"
"This is quaternary structure. Tertiary structure is the folding of a single polypeptide chain."
"The quaternary structure of proteins is the aggregation of polypeptide chains to form biologically active molecules that may have allosteric properties."
"T"
"The quaternary structure of proteins is the aggregation of separate polypeptide chains to form biologically active molecules that may have allosteric properties."
155, blank.bmp
"The tertiary structure of proteins results in part from interactions of hydrophilic amino acid side-chains with water."
"T"
"Tertiary structure of proteins is due to interactions between amino acid side-chains with each other and the environment."
"The primary structure of proteins results in part from interactions of hydrophilic amino acid side-chains with water."
"F"
"The primary structure of a protein is its sequence of amino acids. It is tertiary structure that is due to interactions between amino acid side-chains with each other and the environment."
156, gly.bmp
"This is an acidic amino acid"
"F"
"This is glycine - the side-chain (which is only H) has no charge."
"This is a basic amino acid"
"F"
"This is glycine - the side-chain (which is only H) has no charge."
157, ala.bmp
"This is an acidic amino acid"
"F"
"This is alanine - the side-chain has no charge."
"This is a basic amino acid"
"F"
"This is alanine - the side-chain has no charge."
158, ala.bmp
"This is a neutral amino acid."
"T"
"This is alanine - the side-chain has no charge."
"This is an aromatic amino acid."
"F"
"This is alanine; the side-chain is a methyl group."
159, ala.bmp
"This is an essential amino acid."
"F"
"This is alanine - it is not a dietary essential amino acid."
"This is an essential amino acid."
"F"
"This is alanine - it is not a dietary essential amino acid."
160, ser.bmp
"This is an essential amino acid."
"F"
"This is serine - it is not a dietary essential amino acid."
"This is an essential amino acid."
"F"
"This is serine - it is not a dietary essential amino acid."
161 glu.bmp
"This is an essential amino acid."
"F"
"This is glutamate - it is not a dietary essential amino acid."
"This is an essential amino acid."
"F"
"This is glutamate - it is not a dietary essential amino acid."
162, leu.bmp
"This is an essential amino acid."
"T"
"This is leucine, which is a dietary essential amino acid."
"This is an essential amino acid."
"T"
"This is leucine, which is a dietary essential amino acid."
163, ile.bmp
"This is an essential amino acid."
"T"
"This is isoleucine, which is a dietary essential amino acid."
"This is an essential amino acid."
"T"
"This is isoleucine, which is a dietary essential amino acid."
164, val.bmp
"This is an essential amino acid."
"T"
"This is valine, which is a dietary essential amino acid."
"This is an essential amino acid."
"T"
"This is valine, which is a dietary essential amino acid."
165, met.bmp
"This is an essential amino acid."
"T"
"This is methionine, which is a dietary essential amino acid."
"This is an essential amino acid."
"T"
"This is methionine, which is a dietary essential amino acid."
166, phe.bmp
"This is an essential amino acid."
"T"
"This is phenylalanine, which is a dietary essential amino acid."
"This is an essential amino acid."
"T"
"This is phenylalanine, which is a dietary essential amino acid."
167, trp.bmp
"This is an essential amino acid."
"T"
"This is tryptophan, which is a dietary essential amino acid."
"This is an essential amino acid."
"T"
"This is tryptophan, which is a dietary essential amino acid."
168, asp.bmp
"This is an essential amino acid."
"F"
"This is aspartate, which is not a dietary essential amino acid."
"This is an essential amino acid."
"F"
"This is aspartate, which is not a dietary essential amino acid."
169, asn.bmp
"This is an essential amino acid."
"F"
"This is asparagine, which is not a dietary essential amino acid."
"This is an essential amino acid."
"F"
"This is asparagine, which is not a dietary essential amino acid."
170, gln.bmp
"This is an essential amino acid."
"F"
"This is glutamine, which is not a dietary essential amino acid."
"This is an essential amino acid."
"F"
"This is glutamine, which is not a dietary essential amino acid."
171, ser.bmp
"This is an essential amino acid."
"F"
"This is serine, which is not a dietary essential amino acid."
"This is an essential amino acid."
"F"
"This is serine, which is not a dietary essential amino acid."
172, arg.bmp
"This is an essential amino acid."
"F"
"This is arginine, which is not a dietary essential amino acid."
"This is an essential amino acid."
"F"
"This is arginine, which is not a dietary essential amino acid."
173, thr.bmp
"This is an essential amino acid."
"T"
"This is threonine, which is a dietary essential amino acid."
"This is an essential amino acid."
"T"
"This is threonine, which is a dietary essential amino acid."
174, lys.bmp
"This is an essential amino acid."
"T"
"This is lysine, which is a dietary essential amino acid."
"This is an essential amino acid."
"T"
"This is lysine, which is a dietary essential amino acid."
175, tyr.bmp
"This is a basic amino acid."
"F"
"This is tyrosine, which is a neutral aromatic amino acid."
"This is an aromatic amino acid."
"T" 
"This is tyrosine, which is an aromatic amino acid."
176, phe.bmp
"This is a basic amino acid."
"F"
"This is phenylalanine, which is a neutral aromatic amino acid."
"This is an aromatic amino acid."
"T" 
"This is phenylalanine, which is an aromatic amino acid."
177, trp.bmp
"This is a basic amino acid."
"F"
"This is tryptophan, which is a neutral aromatic amino acid."
"This is an aromatic amino acid."
"T" 
"This is tryptophan, which is an aromatic amino acid."
178, ile.bmp
"This is a basic amino acid."
"F"
"This is isoleucine, which is a large neutral branched-chain amino acid."
"This is an aromatic amino acid."
"F" 
"This is isoleucine, which is a large neutral branched-chain amino acid."
179, val.bmp
"This is a basic amino acid."
"F"
"This is valine, which is a large neutral branched-chain amino acid."
"This is an aromatic amino acid."
"F" 
"This is valine, which is a large neutral branched-chain amino acid."
180, glu.bmp
"This is a basic amino acid."
"F"
"This is glutamate, which is an acidic amino acid."
"This is an acidic amino acid."
"T" 
"This is glutamate, which is an acidic amino acid."
181, asp.bmp
"This is a basic amino acid."
"F"
"This is aspartate, which is an acidic amino acid."
"This is an acidic amino acid."
"T" 
"This is aspartate, which is an acidic amino acid."
182, asn.bmp
"This is a basic amino acid."
"F"
"This is asparagine, which is a neutral amino acid - the amide group does not ionize."
"This is an acidic amino acid."
"F" 
"This is asparagine, which is a neutral amino acid - the amide group does not ionize."
183, gln.bmp
"This is a basic amino acid."
"F"
"This is glutamine, which is a neutral amino acid - the amide group does not ionize."
"This is an acidic amino acid."
"F" 
"This is glutamine, which is a neutral amino acid - the amide group does not ionize."
184, lys.bmp
"This is a basic amino acid."
"T"
"This is lysine, which is a basic amino acid."
"This is an acidic amino acid."
"F" 
"This is lysine, which is a basic amino acid."
185, arg.bmp
"This is a basic amino acid."
"T"
"This is arginine, which is a basic amino acid."
"This is an acidic amino acid."
"F" 
"This is arginine, which is a basic amino acid."
186, his.bmp
"This is a basic amino acid."
"T"
"This is histidine, which is a basic amino acid."
"This is an acidic amino acid."
"F" 
"This is histidine, which is a basic amino acid."
187, thr.bmp
"This is a basic amino acid."
"F"
"This is threonine, which is a neutral amino acid."
"This is an acidic amino acid."
"F" 
"This is threonine, which is a neutral amino acid."
188, cys.bmp
"This is a basic amino acid."
"F"
"This is cysteine, which is a neutral amino acid."
"This is an acidic amino acid."
"F" 
"This is cysteine, which is a neutral amino acid."
189, starch.bmp
"The diagram shows part of a molecule of starch. The bond between two glucose units in region C forms a branch point."
"F"
"This is a 1-4 glycoside bond - between carbon 1 of one glucose unit and carbon 4 of the next. It forms the straight chains of starch (and glycogen)."
"The diagram shows part of a molecule of starch. The bond between two glucose units in region B forms a branch point."
"T"
"This is a 1-6 glycoside bond - between carbon 1 of one glucose unit and carbon 6 of the next. This type of bond forms a branch point in starch (and also in glycogen)."
190, sucrose.bmp
"This is a reducing sugar."
"F"
"This is sucrose; it has no group that can act as a reducing agent."
"This is a monosaccharide."
"F"
"This is sucrose - a disaccharide composed of glucose and fructose."
191, blank.bmp
"Trehalose is a monosaccharide."
"F"
"Trehalose is a disaccharide."
"Maltose is a monosaccharide."
"F"
"Maltose is a disaccharide."
192, blank.bmp
"All monosaccharides have 6 carbon atoms."
"F"
"Monosaccharides may contain between 3 - 7 carbons. The common dietary monosaccharides are 6-carbon sugars."
"Sugar alcohols are formed by reduction of the aldehyde group of sugars."
"T"
"Because they are poorly absorbed, sugar alcohols are commonly used in the preparation of jam and sweets for energy-reduced diets."
193, blank.bmp
"Starch is a linear polymer of glucose."
"F"
"Amylose is a linear polymer of glucose, linked 1-4, but amylopectin contains branch points formed by 1-6 glycoside bonds. Most starches are mixtures of amylose and amylopectin."
"Starch contains both 1-4 and 1-6 glycoside bonds."
"T"
"Amylose is a linear polymer of glucose, linked 1-4, but amylopectin contains branch points formed by 1-6 glycoside bonds. Most starches are mixtures of amylose and amylopectin."
194, blank.bmp
"Glycogen is a branched polymer of glucose."
"T"
"The straight chains of glycogen are formed from glucose units linked 1-4, with branch points formed by 1-6 glycoside bonds."
"Glycogen is a linear polymer of glucose."
"F"
"The straight chains of glycogen are formed from glucose units linked 1-4, with branch points formed by 1-6 glycoside bonds."
195, blank.bmp
"Starch consists entirely of glucose units linked by 1-4 glycoside bonds."
"F"
"Amylose is a linear polymer of glucose, linked 1-4, but amylopectin contains branch points formed by 1-6 glycoside bonds. Most starches are mixtures of amylose and amylopectin."
"Starch consists of glucose units linked by 1-4 and some 1-6 glycoside bonds."
"T"
"Amylose is a linear polymer of glucose, linked 1-4, but amylopectin contains branch points formed by 1-6 glycoside bonds. Most starches are mixtures of amylose and amylopectin."
196, glucose2.bmp
"This compound will reduce an alkaline copper reagent."
"T"
"This is glucose. It has an aldehyde group which acts as a reducing agent and will therefore react with an alkaline copper reagent."
"This compound will not react with an alkaline copper reagent."
"F"
"This is glucose. It has an aldehyde group which acts as a reducing agent, and will therefore react with an alkaline copper reagent."
197, glucose2.bmp
This compound is a sugar alcohol."
"F"
"In a sugar alcohol the aldehyde or ketone group has been reduced to an alcohol (-OH). This is glucose, which has an aldehyde group at carbon-1."
"This compound has a ketone group."
"F"
"This compound has an aldehyde group at carbon-1. This is glucose."
198, fructose.bmp
"This compound is a sugar alcohol."
"F"
"In a sugar alcohol the aldehyde or ketone group has been reduced to an alcohol (-OH). This is fructose, which has a ketone group at carbon-2."
"This compound is a reducing sugar."
"F"
"This is fructose, which has a ketone group at carbon-2; therefore it is not a reducing compound."
199, fructose.bmp
"This compound is absorbed in the small intestine by sodium-dependent active transport."
"F"
"Only glucose and galactose are actively absorbed in the small intestine; this is fructose, which is absorbed by facilitated diffusion."
"This compound is absorbed by facilitated diffusion in the small intestine."
"T"
"Only glucose and galactose are actively absorbed in the small intestine; this is fructose, which is absorbed by facilitated diffusion."
200, blank.bmp
"The fatty acid which is abbreviated to C22:6 n-3 has three double bonds.
"F"
"The number after the colon in the shorthand indicates the number of double bonds in the fatty acid. :6 means a fatty acid with 6 double bonds. n-3 shows that the first double bond is at carbon-6 from the methyl end."
"The fatty acid which is abbreviated to C22:6 n-3 has six double bonds and 22 carbon atoms.
"T"
"The number after the colon in the shorthand indicates the number of double bonds in the fatty acid. C22:6 means a 22-carbon fatty acid with 6 double bonds. n-3 shows that the first double bond is at carbon-6 from the methyl end."
-999


