Chapter 7: Carbohydrates

What is the CORRECT name for the linkage between these monosaccharide derivatives? (a1-B4) (a1- a 4) (a1-4) (1 4) (B1- 4)

(B1- 4)

Describe the structure of the repeating basic unit of amylose and cellulose. In ["amylose", "cellulose"] , the repeating unit is an a-D-glucose linked to a-D-glucose. Therefore, the linkage is ["alpha (1-2)", "beta (1-2)", "alpha (1-4)", "beta (1-4)"] . In ["amylose", "cellulose"] , the repeating units are B-D-glucose. Therefore, the linkage is ["alpha (1-2)", "beta 1-4", "alpha (1-4)", "beta (1-2)"] .

1. amylose 2. alpha 1-4 3. cellulose 4. beta 1-4

Which arrow CORRECTLY identifies the atom that will become the anomeric carbon?

A

Polysaccharides can be used by cells _________________. as fuel storage molecules. for structural elements in animal exoskeletons. for structural elements in cell walls. All of the answers are correct. Polysaccharides can be used for all these purposes by various cells. for the extracellular matrix in animal cells.

All of the answers are correct. Polysaccharides can be used for all these purposes by various cells.

Which statement provides the MOST compelling reason to devote resources to study cellulose-degrading enzymes? Symbiotic microorganisms in digestive tracts could be used as treatments in some GI tract diseases. Humans could use cellulose as a food source. Biomass could be converted more easily to bioenergy. None of the answers is correct. Biomass could be converted to crude oil under high pressure.

Biomass could be converted more easily to bioenergy.

Match the following changes with the bond that must be broken and reformed in the opposite configuration: To convert alpha-D-glucose to beta-D-glucose Bond between C-1 and -OH of C-5 Bond between C-2 and either -H or -OH None-this is a conformational change that does not require bond breakage Bond between C-1 of the first monomer to C-4 of second monomer Bond between C-1 and C-2

Bond between C-1 and -OH of C-5

Match the following changes with the bond that must be broken and reformed in the opposite configuration: To convert D-glucose to D-mannose Bond between C-1 and -OH of C-5 Bond between C-2 and either -H or -OH None-this is a conformational change that does not require bond breakage Bond between C-1 of the first monomer to C-4 of second monomer Bond between C-1 and C-2

Bond between C-2 and either -H or -OH

Following complete hydrolysis of a sample of glycogen and a sample of cellulose, which statement must be TRUE? The glycogen sample has a higher ratio of α-D-glucose than the cellulose sample. The cellulose sample contains only β-D-glucose. The glycogen and cellulose samples are soluble. Both samples consist of a mixture of α-D-glucose and β-D-glucose.

Both samples consist of a mixture of α-D-glucose and β-D-glucose.

Which statement about starch and glycogen is FALSE? Amylose is unbranched; amylopectin and glycogen contain many (α1 → 6) branches. Both are homopolymers of glucose. Glycogen is more extensively branched than starch. Both starch and glycogen are stored intracellularly as insoluble granules. Both serve primarily as structural elements in cell walls.

Both serve primarily as structural elements in cell walls.

From the abbreviated name of the compound Gal(1 4)Glc, we know that: the glucose residue is the B anomer. the compound is a D-enantiomer. the glucose is in its pyranose form. the galactose residue is at the reducing end. C-4 of glucose is joined to C-1 of galactose by a glycosidic bond.

C-4 of glucose is joined to C-1 of galactose by a glycosidic bond.

Which statement about cellulose is TRUE? Cellulose is the main storage polysaccharide of animal cells. Cellulose is a homopolysaccharide with beta 1-4 linkages. Cellulose is a highly branched polysaccharide. Cellulose cannot be broken down by invertebrate animals. Cellulose glucose residues contain the same configuration as amylose glucose residues.

Cellulose is a homopolysaccharide with beta 1-4 linkages.

Which pair is epimeric? D-lactose and D-sucrose D-glucose and L-glucose D-glucose and D-glucosamine D-glucose and D-mannose L-mannose and L-fructose

D-glucose and D-mannose

Describe how the following pairs are DIFFERENT: cellulose and glycogen One is an aldose and one is a ketose One is a monosaccharide and one is a disaccharide Difference in glycosidic linkage One is a triose and one is a hexose Difference in the type of monomers of which they are composed

Difference in glycosidic linkage

Describe how the following pairs are DIFFERENT: maltose and sucrose One is an aldose and one is a ketose One is a monosaccharide and one is a disaccharide Difference in glycosidic linkage One is a triose and one is a hexose Difference in the type of monomers of which they are composed

Difference in the type of monomers of which they are composed

Based on the form of the cyclic sugar shown below in a Haworth projection, which Fischer projection formula could have formed this structure?

Figure A In D and E, the -OH groups on C3 and C4 are both either "up" (Left in Fischer) or "down" (Right in Fischer)

____ could be used to determine human blood group type. Globoside Lipopolysaccharides Lipoproteins Mucins Glycoproteins

Globoside

When drawing a Haworth perspective formula from a Fisher projection, which statement is TRUE regarding anomers? It is a if the hydroxyl group on the anomeric carbon is down. It is a if the hydroxyl group on the anomeric carbon on the opposite side of the ring as the C6. It is a if the hydroxyl group on the anomeric carbon on the same side of the ring as the C6. It is a if the hydroxyl group on the anomeric carbon is up.

It is a if the hydroxyl group on the anomeric carbon on the opposite side of the ring as the C6.

Which disaccharide does NOT have an anomeric carbon available for oxidation? Glc (a1 - 1a) Glc both Glc (a1 - 2B) Fru and Fru (B2 - 1a) Glc None of the above Glc (a1 - 2B) Fru Fru (B2 - 1a) Glc

None of the above

During which process are chemical bonds NOT broken? interconverting between two anomers mutarotation None of the answers is correct: all involve breaking a chemical bond. interconverting between two configurations

None of the answers is correct: all involve breaking a chemical bond

Match the following changes with the bond that must be broken and reformed in the opposite configuration: to convert one "chair" form of D-glucose to the other Bond between C-1 and -OH of C-5 Bond between C-2 and either -H or -OH None-this is a conformational change that does not require bond breakage Bond between C-1 of the first monomer to C-4 of second monomer Bond between C-1 and C-2

None-this is a conformational change that does not require bond breakage

Describe how the following pairs are DIFFERENT: D-glucose and D-fructose One is an aldose and one is a ketose One is a monosaccharide and one is a disaccharide Difference in glycosidic linkage One is a triose and one is a hexose Difference in the type of monomers of which they are composed

One is an aldose and one is a ketose

Explain why all mono- and disaccharides are soluble in water. These are soluble due to the carbonyl and methyl groups. These compounds have many hydroxyl groups, each of which can hydrogen bond with water. These compounds are not fully soluble in water. These compounds have many Carbon and Hydrogen atoms which have an affinity for water.

These compounds have many hydroxyl groups, each of which can hydrogen bond with water.

Which commonality does NOT exist between peptides, nucleic acids, and poly- and oligosaccharides? They are all information-carrying molecules. They are all created from multiple building blocks. All of the answer choices are commonalities between peptides, nucleic acids, and poly- and oligosaccharides. The sequence of monomers is important for function. They are all synthesized from a template.

They are all synthesized from a template.

Enzymes that act on carbohydrate polymers to mobilize glucose for metabolism act only on their nonreducing ends. Describe one biological advantage of storing glucose units in branched polymers (glycogen, amylopectin) rather than in linear polymers. Branched polymers are not able to stack in storage cells. Nonreducing ends are not as available in the branched form as compared to the linear form. With extensive branching, there are more such ends for enzymatic attack than would be present in the same quantity of glucose stored in a linear polymer. There is no advantage.

With extensive branching, there are more such ends for enzymatic attack than would be present in the same quantity of glucose stored in a linear polymer.

Which pair is interconverted in the process of mutarotation? D-glucose and D-fructose D-glucose and D-glucosamine D-glucose and D-galactose D-glucose and L-glucose a-D-glucose and B-D-glucose

a-D-glucose and B-D-glucose

Starch and glycogen are both polymers of: a-D-glucose. sucrose. glucose1-phosphate. B-D-glucose. fructose.

a-D-glucose.

_In aldoses and ketoses, the anomeric carbon is the carbon which is the ___________ a. carbonyl b. enantiomers c. anomeric d. hemiacetal e. glycosidic f. acetal g. epimer

a. carbonyl

a sugar with an aldehyde carbonyl group. furanose pyranose aldose ketose reducing sugar

aldose

In a(n) _____ the carbonyl group is at the end of the carbon chain, but in a(n) _____ the carbonyl group can be at any other position. aldose; ketose ketose; tetrose aldose; hexose ketose; aldose

aldose; ketose

In glycoproteins, the carbohydrate moiety is always attached through the amino acid residues: aspartate or glutamate. glutamine or arginine. asparagine, serine, or threonine. glycine, alanine, or aspartate.

asparagine, serine, or threonine.

____________ are stereoisomers that are non-superimposable mirror images of each other. a. carbonyl b. enantiomers c. anomeric d. hemiacetal e. glycosidic f. acetal g. epimer

b. enantiomers

In most cases, in order for an informational carbohydrate to become a biologically active molecule, it must: be present in the extracellular matrix. be covalently joined to a protein or lipid. contain a reducing sugar. contain an O-glycosidic bond.

be covalently joined to a protein or lipid.

A glycoconjugate molecule may include a carbohydrate as well as: a saccharide. both an amino acid and a lipid. a lipid. an amino acid.

both an amino acid and a lipid.

Which polysaccharide(s) can the enzyme -amylase break? cellulose both glycogen and cellulose both glycogen and starch starch glycogen

both glycogen and starch

an _______________ carbon in a sugar is a new stereocenter formed when a sugar cyclizes to form a hemiacetal.. a. carbonyl b. enantiomers c. anomeric d. hemiacetal e. glycosidic f. acetal g. epimer

c. anomeric

The polysaccharide chitin is MOST chemically similar to: amylose. glycogen. dextran. cellulose. starch.

cellulose

In amylose, the most stable structure is a _____, which is stabilized by _____. coiled helix; hydrogen bonds to surrounding water molecules coiled helix; interchain covalent branching coiled helix; interchain hydrogen bonds straight, extended chain; interchain hydrogen bonds straight, extended chain; hydrogen bonds to surrounding water molecules

coiled helix; interchain hydrogen bonds

An ______________ is a carbon with one ether attached (R - O - R'). The reducing end of mannose is an example of this. a. carbonyl b. enantiomers c. anomeric d. hemiacetal e. glycosidic f. acetal g. epimer

d. hemiacetal

An _______________ is formed when a hydroxyl group (-OH) of one sugar residue reacts with the anomeric carbon of a second sugar. a. carbonyl b. enantiomers c. anomeric d. hemiacetal e. glycosidic bond f. acetal g. epimer

e. glycosidic bond

An _____________ is a carbon with two ethers attached (R - O - R'). Monosaccharides are examples. a. carbonyl b. enantiomers c. anomeric d. hemiacetal e. glycosidic f. acetal g. epimer

f. acetal

Which of the following monosaccharides is NOT an aldose? ribose erythrose fructose glucose glyceraldehyde

fructose

a sugar with a five-membered ring. furanose pyranose aldose ketose reducing sugar

furanose

are stereoisomers that differ at ONE carbon asymmetric center (where there are multiple asymmetric centers) . They are NOT mirror images a. carbonyl b. enantiomers c. anomeric d. hemiacetal e. glycosidic f. acetal g. epimer

g. epimer

Which monosaccharides is NOT a carboxylic acid? glucuronate muramic acid 6-phospho-gluconate gluconate glucose

glucose

The basic structure of a proteoglycan consists of a core protein and a: glycosaminoglycan. glycolipid. lectin. peptidoglycan. lipopolysaccharide.

glycosaminoglycan

Which polysaccharide is NOT a homopolysaccharide? glycosaminoglycan glycogen dextran amylose chitin

glycosaminoglycan

When the linear form of glucose cyclizes, the product is a(n): lactone. hemiacetal. glycoside. anhydride. oligosaccharide.

hemiacetal

Which compound is a heteropolysaccharide? chitin starch hyaluronate cellulose glycogen

hyaluronate

a sugar with a ketose carbonyl group furanose pyranose aldose ketose reducing sugar

ketose

Which compound(s) is/are a dominant feature of the outer membrane of the cell wall of gram-negative bacteria? amylose glycoproteins lipopolysaccharides cellulose

lipopolysaccharides

a sugar with a six-membered ring. furanose pyranose aldose ketose reducing sugar

pyranose

a sugar with a free carbonyl carbon (aldehyde) that can be oxidized to the carboxylic acid by Cu2+ or Fe3+. furanose pyranose aldose ketose reducing sugar

reducing sugar

Which monosaccharide is NOT a six-carbon monosaccharide? ribose glucose mannose fructose galactose

ribose

The biochemical property of lectins that is the basis for most of their biological effects is their ability to bind to: specific oligosaccharides. specific lipids. specific peptides. amphipathic molecules. hydrophobic molecules.

specific oligosaccharides.

Which compound is NOT a reducing sugar? ribose fructose glucose glyceraldehyde sucrose

sucrose

When two carbohydrates are epimers: one is a pyranose, the other a furanose. they differ in length by one carbon. they rotate plane-polarized light in the same direction. one is an aldose, the other a ketose. they differ only in the configuration around one carbon atom.

they differ only in the configuration around one carbon atom.