Biochem ch 16

The preferred energy source of the brain is __________. A) Fructose B) Glucose C) Arabinose D) Maltose E) Sucrose

B

Which of the following sugars contains a -1,4-linkage? A) Cellulose B) Glucose C) Amylose D) Sucrose E) Maltose

A) Cellulose

29) The two polysaccharides used to store glucose as an energy reserve are starch and _____________. A) Glycogen B) Cellulose C) Fructose D) Sucrose E) Maltose

A) Glycogen

44) Glycomics is defined as: A) Investigation of the structure and function of all glycans in a cell. B) Glycosidology C) Glycology D) Lipology E) Saccariology

A) Investigation of the structure and function of all glycans in a cell.

12) The two most common deoxy sugars are deoxyribose and _________. A) L-Fucose B) Deoxyglucose C) Deoxyarabinose D) L-Sorbose E) D-Sorbose

A) L-Fucose

In glycoproteins carbohydrate is most often linked to threonine, asparagine or __________. A) Serine B) Lysine C) Valine D) Aspartic acid E) Tyrosine

A) Serine

Of the following primary types of taste perception which is the most important in identifying calorie-dense foods? A) Sweet B) Savory C) Sour D) Salty E) A and B

A) Sweet

The principle means of protection of plants against herbivores is A) Taste B) Smell C) Poison D) Mimicry E) Color

A) Taste

The glycome is A) The total set of sugars and glycans that an organism produces B) The total set of sugars that an organism produces C) The total set of glycans that an organism produces D) The glycoforms produced by a single sugar E) None of the above is correct

A) The total set of sugars and glycans that an organism produces

22) A glycosidic link is chemically an _____. A) Ether B) Ester C) Amide D) Aldehyde E) Ketone

A) ether

Oligosaccharides usually contain between ________ and ______simple sugar units. A) 6, 8 B) 2, 10 C) 1, 10 D) 3, 10 E) 7, 10

B) 2, 10

Savory taste detects which of the following? A) Sugars B) Amino acids C) Toxicity D) Electrolytes E) Acids

B) Amino acids

21) Cellulose is indigestible to most animals because: A) Cellulose is not soluble in water B) Animals lack the enzymes required to hydrolyse the links of the cellulose C) Cellulose has no food value and therefore cannot be digested D) Both A and B are correct E) None of the above are correct.

B) Animals lack the enzymes required to hydrolyse the links of the cellulose

The most abundant organic substance on earth is ______. A) Starch B) Cellulose C) Sucrose D) Glucose E) Both B and D are correct

B) Cellulose

Translation of the sugar code requires which of the following? A) Glycoforms B) Lectins C) RNA D) DNA E) Integrins

B) Lectins

Glycoconjugates result from the covalent linkage of carbohydrate to proteins or _________ A) Amino acids B) Lipids C) Nucleotides D) Both A and B are correct E) None of the above is correct

B) Lipids

Glycogen is: A) Main energy storage molecule of animals B) Main carbohydrate reserve of animals C) Main carbohydrate found in seeds D) A form of plant starch E) Both C and D are correct

B) Main carbohydrate reserve of animals

Carbohydrate is thought to enhance the stability of protein molecules by: A) Changing the protein's shape to better resist denaturation. B) Protecting the underlying protein from the action of proteolytic enzymes C) Using hydrogen bonding to increase the stability of the protein D) Both A and B are correct E) All of the above are correct

B) Protecting the underlying protein from the action of proteolytic enzymes

Lactose intolerance arises from A) Bacteria in the intestine that produce toxic metabolites B) The inability of intestinal enzymes to cleave the lactose C) A sensitivity to galactose D) A sensitivity to glucose E) An allergic reaction to glucose

B) The inability of intestinal enzymes to cleave the lactose

N-Glycans are linked via a ______ link between the carbohydrate and the amino acid. A) alpha-Glycosidic B) beta-Glucosidic C) Ester D) Amide E) Both A and B are correct

B) beta-Glucosidic

Which of the following yields N-acetyl-D-glucosamine on hydrolysis. A) Cellulose B) Heparin C) Chitin D) Amylopectin E) Amylose

C) Chitin

Which of the following sugars lacks a chiral center A) Glucose B) Glyceraldehyde C) Dihydroxyacetone D) Ribose E) Fructose

C) Dihydroxyacetone

Reaction of an amino acid with C1 of a cyclic aldose produces which of the following linkages? A) Ester B) Amide C) Glycosidic D) Imine E) Schiff base

C) Glycosidic

33) Which of the following is not a common sugar found in N-glycans? A) Mannose B) Glucose C) Maltose D) Fucose E) Galactose

C) Maltose

The production of the glycan components of each type of glycoprotein as a series of slightly different forms is referred to as A) Glycoformation B) Glycolation C) Microheterogeneity D) Posttranslational modification E) Alternative splicing

C) Microheterogeneity

Amylopectin is a form of ________. A) Cellulose B) Lactose C) Starch D) Glycogen E) Amylose

C) Starch

The principal structural carbohydrate of plants is _________ A) Starch B) Glycogen C) Cellulose D) Amylose E) Xylulose

C) cellulose

How many stereoisomers are possible for an aldohexose A) 4 B) 8 C) 12 D) 16 E) 32

D) 16

Glycoproteins lack which of the following groups typically found in proteoglycans? A) Uronic acids B) Sulfate groups C) N-Glycosidic linkages D) Both A and B are correct E) All of the above are correct

D) Both A and B are correct

The three most common homoglycans found in nature are cellulose, starch, and __________. A) Amylose B) Lactose C) Fructose D) Glycogen E) Sucrose

D) Glycogen

Which of the following is not a homoglycan? A) Cellulose B) Glycogen C) Starch D) Heparin E) Amylose

D) Heparin

Which of the following polysaccharides can bind exceptionally large amounts of water? A) Cellulose B) Glycogen C) Starch D) Heparin E) Amylose

D) Heparin

Which of the following terms is not associated with glycation reactions? A) AGEs B) Amadori products C) Adduct D) Lactose E) Maillard reaction

D) Lactose

The accumulation of AGEs is linked to which of the following diseases? A) Atherosclerosis B) Arthritis C) Diabetes D) Both A and B are correct E) All of the above are correct

E) All of the above are correct

Which of the following is an example of posttranslational modification of proteins? A) Phosphorylation B) Acetylation C) Proteolytic cleavage D) Glycosylation E) All of the above are examples of posttranslational modification

E) All of the above are examples of posttranslational modification

In an aldohexopyranose how many methyl groups will be incorporated on treatment with methyl iodide? A) One B) Two C) Three D) Four E) Five

E) Five

The following sugar is also called fruit sugar: a. Fructose b. Glucose c. Lactose d. Sucrose e. Maltose

a. Fructose

Two samples containing identical mixtures of sugars are analyzed, one using Tollen's reagent, the other with glucose oxidase. Which will give a stronger reaction? a. Tollen's reagent b. glucose oxidase c. They will have identical strengths. d. It's impossible to predict from the information provided.

a. Tollen's reagent

Glycogen breakdown proceeds from the nonreducing ends. a. True b. False

a. True

Insoluble fiber in the diet is better at better at providing bulk and stimulating peristaltic action than soluble fiber. a. True b. False

a. True

One advantage of branched sugar polymers is the availability of more ends for chemical reaction. a. True b. False

a. True

One major difference between bacterial and plant cell walls is that bacterial cell walls have polysaccharides that are crosslinked by peptides. a. True b. False

a. True

The conversion of a sugar's carbonyl to an alcohol is a. a reduction reaction. b. an oxidation reaction. c. a glycosidic reaction. d. impossible.

a. a reduction reaction

Which of the following is true about the ABO blood groups? a. all three of the blood groups have an á-L-fucose group attached b. type O blood is the universal donor because it has an á-L-fucose group c. type A blood has a â-N-acetylgalactosamine group d. type AB blood is the universal donor

a. all three of the blood groups have an á-L-fucose group attached

The α and β forms of the same sugar are called a. anomers. b. diastereoisomers. c. enantiomers. d. epimers. e. none of these

a. anomers

Lactose intolerance a. arises from inability to metabolize the disaccharide lactose b. depends on a deficiency of sucrose in the diet c. is based on the composition of lactose, consisting glucose and fructose in glycosidic linkage d. arises because lactose is a dimer of galactose

a. arises from inability to metabolize the disaccharide lactose

Which of the following disaccharides cannot be digested by mammals? a. cellobiose b. sucrose c. maltose d. lactose

a. cellobiose

A furanose is a sugar that a. contains a five-membered ring as part of its cyclic structure. b. contains a six-membered ring as part of its cyclic structure. c. is a five-carbon open-chain sugar. d. is a six-carbon open-chain sugar.

a. contains a five-membered ring as part of its cyclic structure.

The cyclic form of sugars a. has one more chiral center (the anomeric carbon) than the open-chain form. b. loses a chiral center compared to the open-chain form. c. is not usually found in nature. d. has one more carbon atom than the open-chain form. e. has one less carbon atom than the open-chain form.

a. has one more chiral center (the anomeric carbon) than the open-chain form.

Aldoses can form which type of cyclic structure? a. Hemiacetal b. Hemiketal c. Both hemiacetal and hemiketal d. Neither hemiacetal and hemiketal

a. hemiacetal

Which of the following is true about Sucralose a. it is an artificial sweetener b. It is exactly like sucrose except for the presence of 3 chlorine atoms c. It is a dissacharide made up of glucose and fructose d. all of these

a. it is an artificial sweetener

Which carbon of the open-chain form of a sugar becomes the anomeric carbon in the cyclic form? a. the carbonyl carbon b. the highest numbered chiral center c. the highest numbered carbon d. It depends on the individual sugar.

a. the carbonyl carbon

Blood typing depends on a. the nature of the oligosaccharide portion of glycoproteins on the surface of red blood cells b. the presence of a polysaccharide coating on red blood cells c. the presence of a polysaccharide coating on white blood cells d. the addition of sucrose to blood before storage

a. the nature of the oligosaccharide portion of glycoproteins on the surface of red blood cells

Glycogen is sometimes called animal starch a. True b. False

a. true

A bacterial cell wall is composed of: a. A polysaccharide consisting of a single type of monosaccharide unit and cross-linking oligopeptides. b. A polysaccharide consisting of 2 types of monosaccharide units and cross-linking oligopeptides. c. A polysaccharide consisting of 3 types of monosaccharide units and cross-linking oligopeptides. d. Two different polysaccharides and 1 type of oligopeptide, which are cross-linked.

b. A polysaccharide consisting of 2 types of monosaccharide units and cross-linking oligopeptides.

Which of the following has only α[1−4] linkages and no α[1−6] linkages a. Glycogen b. Amylose c. Amylopectin d. Starch e. Cellobiose

b. Amylose

The most common biopolymer on earth is this carbohydrate: a. Glucose b. Cellulose c. Starch d. Chitin e. None of these carbohydrates is very common

b. Cellulose

Glycogen has a similar structure to amylopectin, but is less highly branched. a. True b. False

b. False

Plant starch includes amylopectin and cellulose a. True b. False

b. False

Which of the following statements concerning sugar polymers is false? a. Branched polymers have one non-reducing end and many reducing ends. b. Linear polymers are more water-soluble than branched ones. c. Branched polymers are more water-soluble than linear ones. d. Sugar polymers may vary both in the composition of the sugar monomers and in the types of connecting glycosidic bonds.

b. Linear polymers are more water-soluble than branched ones.

Cell walls a. occur in plants, animals, and bacteria b. are found in plants and bacteria, but have different chemical compositions c. have the same chemical composition in plants and bacteria d. have the same chemical composition in plants and animals

b. are found in plants and bacteria, but have different chemical compositions

Glycoproteins a. are involved in the metabolism of sugars b. are proteins to which sugars are covalently bonded c. occur in the bloodstream of diabetics d. have not been found in nature, but have been synthesized in the laboratory

b. are proteins to which sugars are covalently bonded

Which of the following groups is produced when an aldehyde is oxidized? a. ketone b. carboxyl c. alcohol d. ether

b. carboxyl

A pyranose is a sugar that a. contains a five-membered ring as part of its cyclic structure. b. contains a six-membered ring as part of its cyclic structure. c. is a five-carbon open-chain sugar. d. is a six-carbon open-chain sugar.

b. contains a six-membered ring as part of its cyclic structure.

The simplest ketotriose is a. glyceraldehyde. b. dihydroxyacetone. c. ribose. d. glucose. e. sucrose.

b. dihydroxyacetone.

A lactone is a cyclic a. ether. b. ester. c. ketone. d. alcohol.

b. ester.

Insoluble fiber in the diet is better at binding toxic substances than soluble fiber. a. True b. False

b. false

Polysaccharides used in cell wall structure contribute rigidity to the wall due to covalent cross-linking between the fibers. a. True b. False

b. false

Which of the following monosaccharides is a ketose? a. glucose b. fructose c. galactose d. mannose

b. fructose

Maltose is composed of the following simple sugars: a. galactose only b. glucose only c. fructose only d. galactose and glucose e. glucose and fructose f. galactose and fructose

b. glucose only

For the α anomer of a D-sugar, the anomeric hydroxyl in a Haworth projection a. has an upward projection (on the same side as the terminal CH2OH group). b. has a downward projection (on the opposite side from the terminal CH2OH group). c. may be either up or down, it depends on the individual sugar. d. is non-existent; anomers are a consideration only in Fischer projections.

b. has a downward projection (on the opposite side from the terminal CH2OH group).

For a D-sugar, any group that is written to the right of the carbon in a Fischer projection a. has an upward projection in a Haworth projection. b. has a downward projection in a Haworth projection. c. may be either up or down in a Haworth projection, it depends on the individual sugar. d. is missing from a Haworth projection.

b. has a downward projection in a Haworth projection.

Which of the following molecules is a disaccharide? a. glucose b. lactose c. fructose d. galactose

b. lactose

Diastereomers are a. mirror-image, nonsuperimposable stereoisomers. b. non-mirror-image, nonsuperimposable stereoisomers. c. stereoisomers with one or more double bonds. d. none of the above.

b. non-mirror-image, nonsuperimposable stereoisomers

Epimers are a. stereoisomers that differ from each other in their configuration at two or more carbon atoms. b. stereoisomers that differ from each other in their configuration at a single carbon atom. c. the α and β forms of cyclic sugars. d. two related compounds, pyran and furan.

b. stereoisomers that differ from each other in their configuration at a single carbon atom.

The main difference, on the surface of a red blood cell, between the A-B-O major blood groups depends on a. the presence or absence of a certain protein sequence. b. the presence or absence of a certain sugar. c. the presence or absence of an acetyl group on a sugar. d. all of these

b. the presence or absence of a certain sugar.

Chitin, which forms the exoskeletons of insects, is composed of a. α(1−4) linked N-acetylglucosamine residues b. β(1−4) linked N-acetylglucosamine residues c. α(1−4) linked glucose residues d. β(1−4) linked glucose residues

b. β(1−4) linked N-acetylglucosamine residues

How many carbon atoms are in the simplest carbohydrates? a. 1 b. 2 c. 3 d. 4 e. 5

c. 3

How many enantiomeric pairs are possible for a aldohexose? a. 2 b. 4 c. 8 d. 16

c. 8

The linkage between the glucose residues in amylopectin and glycogen is: a. For the main chain α (1 → 4) and β (1 → 4) for the branches b. For the main chain α (1 → 6) and α (1 → 4) for the branches c. For the main chain α (1 → 4) and α (1 → 6) for the branches d. For the main chain β (1 → 4) and β (1 → 6) for the branches e. The linkage between the glucose residues is variable.

c. For the main chain α (1 → 4) and α (1 → 6) for the branches

The following sugar is also called milk sugar: a. Fructose b. Glucose c. Lactose d. Sucrose e. Maltose

c. Lactose

Which of the following types of carbohydrates are made up of sugars linked by glycosidic bonds? a. Monosaccharides b. Aldoses c. Oligosaccharides d. Ketoses

c. Oligosaccharides

Glycogen is a. polysaccharide storage polymer found in plants b. a linear polysaccharide c. a highly branched polysaccharide found in animals d. a synthetic sugar substitute

c. a highly branched polysaccharide found in animals

Which of the following compounds is produced by oxidation of an aldose in the cyclic form? a. a hemiacetal b. a hemiketal c. a lactone d. an amino sugar

c. a lactone

A major difference between amylose and amylopectin is that a. amylose is connected by α(1−4) bonds and amylopectin is connected by β(1−4) bonds. b. amylose is branched and amylopectin is not. c. amylopectin is branched and amylose is not. d. each is composed different types of sugar residues.

c. amylopectin is branched and amylose is not.

Cellulose is indigestible to most animals because a. animals do not have the enzymes needed to hydrolyze ester linkages between the monomer units b. animals do not have the enzymes needed to hydrolyze the α-glycosidic linkages between the monomer units c. animals do not have the enzymes needed to hydrolyze the β-glycosidic linkages between the monomer units d. its molecular weight is too high for it to be degraded by enzymes

c. animals do not have the enzymes needed to hydrolyze the β-glycosidic linkages between the monomer units

Haworth projection formulas a. are representations of the cyclic form of sugars b. can show the distinction between the α and β anomers c. both of the above d. neither of the above

c. both of the above (a. are representations of the cyclic form of sugars b. can show the distinction between the α and β anomers)

Glycosidic linkages between monosaccharide units may vary based on a. the anomeric form of the cyclic structure, i.e., α or β. b. which −OH group is involved. c. both of these d. none of these

c. both of these

Mirror image stereoisomers are called a. anomers. b. diastereoisomers. c. enantiomers. d. epimers.

c. enantiomers.

The simplest aldotriose is: a. acetone b. dihydroxyacetone c. glyceraldehyde d. threose

c. glyceraldehyde

Glycosidic bonds from sugars a. always link to the other molecule through an oxygen atom. b. always link to the other molecule through a nitrogen atom. c. may link to the other molecule through either an oxygen or a nitrogen atom d. none of these

c. may link to the other molecule through either an oxygen or a nitrogen atom

In bacterial cell walls a. polysaccharides form nonspecific mixtures with proteins b. polysaccharides are hydrogen bonded together c. peptides form crosslinks between polysaccharides d. oligosaccharides form crosslinks between proteins

c. peptides form crosslinks between polysaccharides

Common table sugar is a. glucose b. fructose c. sucrose d. maltose e. lactose

c. sucrose

Which of the following is not a reducing sugar? a. glucose b. fructose c. sucrose d. maltose e. lactose

c. sucrose

The blue color in a well-known test for the presence of starches is due to a. the formation of crosslinks between molecules of starch, caused by the addition of Cu2+ b. the reaction of the silver-ammonia complex ion with the hydroxyl groups of the starch c. the formation of a complex between iodine and amylose d. none of these

c. the formation of a complex between iodine and amylose

Cartilage and mucous are both slippery because: a. Short polymers comprise these compounds. b. The charge repulsion between the many acid groups in these polymers. c. The sticky nature of sugars. d. Both charge repulsion of acidic groups and the sticky nature of sugars. e. All of these

d. Both charge repulsion of acidic groups and the sticky nature of sugars.

Humans are not able to digest cellulose as a food source because: a. Cellulose is very insoluble. b. It is more important that the cellulose is used as fiber in our bodies. c. We lack the enzyme to break the β linkage in the cellulose. d. Cellulose is insoluble and we lack the enzyme to break the β linkage in the cellulose. e. All of these are reasons why we cannot digest cellulose.

d. Cellulose is insoluble and we lack the enzyme to break the β linkage in the cellulose.

Which of the following molecules have the highest degree of α[1−6] branching linkages a. Amylose b. Amylopectin c. Starch d. Glycogen e. All of these have the same degree of branching

d. Glycogen

Which of the following statements associated with cellulose is false? a. It's a linear polymer of glucose. b. The glycosidic linkage is β(1 → 4). c. Hydrolysis is accomplished enzymatically by cellulase. d. Most animals can easily digest this compound.

d. Most animals can easily digest this compound.

Which of the following is not a function of carbohydrates? a. They are major energy sources. b. They play key roles in processes that take place on the surface of cells. c. They are used in structural roles. d. They are catalytic components of enzymes.

d. They are catalytic components of enzymes.

Which of the following statements concerning plant cell walls is false? a. They are composed of a polysaccharide and protein matrix. b. They contain a lipid bilayer. c. They are porous to small molecules. d. They contain large amounts of protein.

d. They contain large amounts of protein.

When monosaccharides are bonded together a. one H2O molecule is lost for each new link formed. b. oligosaccharides are formed by combining a few monosaccharides. c. polysaccharides are formed by combining many monosaccharides. d. all of these

d. all of these

There are two forms of starch: a. amylose and glycogen, both of which are highly branched polysaccharides b. glycogen and chitin, both of which are linear polysaccharides c. amylopectin and glycogen, both of which are linear polysaccharides d. amylose, which is a linear polysaccharide, and amylopectin, which is highly branched

d. amylose, which is a linear polysaccharide, and amylopectin, which is highly branched

Sugars which differ in chirality only around one carbon are most specifically called a. anomers. b. diastereoisomers. c. enantiomers. d. epimers. e. none of these

d. epimers

Lactose is composed of the following simple sugars: a. galactose only b. glucose only c. fructose only d. galactose and glucose e. glucose and fructose f. galactose and fructose

d. galactose and glucose

In a Fischer projection, which chiral carbon determines whether the sugar is the D- or the L-isomer? a. highest numbered carbon atom b. lowest numbered asymmetric carbon atom c. lowest numbered carbon atom d. highest numbered asymmetric carbon atom

d. highest numbered asymmetric carbon atom

The difference between cellobiose and maltose is: a. one contains glucose and the other fructose b. they contain different monosaccharides c. they both contain glucose units but are connected together at different carbons d. one has an á linkage and the other a â linkage e. there is no difference between the two

d. one has an á linkage and the other a â linkage

Amino or acid derivatives of sugars are very important in which of the following biological functions? a. Structural roles b. Lubricating fluids c. Cell surface sugars used in cell identity d. Both structural roles and lubricating fluids. e. All of the above are functions of amino and acid sugar derivatives.

e. All of the above are functions of amino and acid sugar derivatives.

Which of the following monosaccharides is an aldose a. glucose b. galactose c. mannose d. ribose e. all of them

e. all

Which of the following is a disaccharide? a. sucrose b. lactose c. maltose d. cellobiose e. all of them

e. all of them

Sucrose is composed of the following simple sugars: a. galactose only b. glucose only c. fructose only d. galactose and glucose e. glucose and fructose f. galactose and fructose

e. glucose and fructose

Which of the following monosaccharides is a ketose? a. arabinose b. ribose c. xylose d. lyxose e. none of them

e. none of them

Isomers of sugars in which the position of ketone and aldehyde groups have been changed are called a. anomers. b. diastereoisomers. c. enantiomers. d. epimers. e. none of these

e. none of these

Deoxyribose is best described as a(n): a. oxidized form of ribose b. reduced pyranose c. polyhydroxyl alcohol d. glycoside e. reduced form of a pentose

e. reduced form of a pentose