Chapter 5 Study Area Review

What is the major difference between amylose and amylopectin? -Amylose is a straight-chain polymer of glucose, whereas amylopectin is highly branched. -Amylose is composed of glucose, whereas amylopectin is a ribose polymer. -Amylose is the storage polysaccharide found in plants. Amylopectin is a storage polysaccharide of animals. -Most animal cells have enzymes that readily digest amylopectin but not amylose.

Amylose is a straight-chain polymer of glucose, whereas amylopectin is highly branched.

Both starch and cellulose are glucose polymers. Why can animals easily degrade starch, but not cellulose? -The glucose of cellulose has amino functional groups that participate in the formation of glycosidic bonds. Animals do not have the enzymes necessary to degrade these bonds. -Animals have enzymes that can degrade a-1,4-glycosidic bonds, but not a-1,6-glycosidic bonds. -A much greater amount of energy is required in order to degrade cellulose compared to starch. -Starch is a normal part of animals' diets while cellulose is not. -Animals have enzymes that can degrade a-1,4-glycosidic bonds, but not b-1,4-glycosidic bonds.

Animals have enzymes that can degrade a-1,4-glycosidic bonds, but not b-1,4-glycosidic bonds.

Which chemical formula could represent a monosaccharide? -C5H10O10 -C3H6O3 -C2H2O3 -C6H12O3 -C3H3O3

C3H6O3

Which of the following bonds found in carbohydrates have the lowest potential energy? -Carbon-oxygen (C-O) bonds -Carbon-oxygen (C-O), carbon-hydrogen (C-H), and carbon-carbon (C-C) bonds all have the same potential energy. -Carbon-carbon (C-C) bonds -Carbon-hydrogen (C-H) bonds

Carbon-oxygen (C-O) bonds

Which of the following polysaccharides contains a modified monosaccharide? -Cellulose -Glycogen -Chitin -Starch

Chitin

Which of the following statements accurately compares the different polysaccharides? -Chitin is found only in fungi, cellulose in plants and many algae, and peptidoglycan in bacteria. -Cellulose and peptidoglycan are effective structural molecules, whereas chitin is primarily important for energy storage. -Chitin, cellulose, and peptidoglycan consist of long, parallel strands linked to one another. -Peptidoglycan is less complex and more abundant than either chitin or cellulose.

Chitin, cellulose, and peptidoglycan consist of long, parallel strands linked to one another.

As a defense mechanism, the barley plant produces an enzyme called chitinase that breaks down the polysaccharide chitin found in certain pathogens. Which of the following statements describes the protective action of chitinase? -Chitinase disrupts the cell walls of fungal plant pathogens. -Chitinase destroys the sugar needed for pathogens to recognize and infect plant cells. -Chitinase disrupts the cell walls of bacterial plant pathogens. -Chitinase prevents the ability of fungal cells to divide due to a lack of available energy. -Chitinase cannot be expressed by plant cells because chitinase would degrade the chitin needed by plants for energy storage.

Chitinase disrupts the cell walls of fungal plant pathogens.

What is an important function of glycoproteins in animal cells? -Glycoproteins catalyze metabolic reactions. -Glycoproteins contribute to the hydrophobicity of the cell membrane. -Glycoproteins serve as energy storage. -Glycoproteins are important in cell-cell recognition.

Glycoproteins are important in cell-cell recognition.

Which of the following statements regarding polysaccharide polymerization is false? -Polymerization results from a condensation reaction between the hydroxyl groups of two monosaccharides. -Glycosidic linkages connect monomers together in a polymer. -Glycosidic linkages form between the same locations of monomers giving polymers a standard backbone structure. -Hydrolysis cleaves glycosidic linkages to release monomers from polysaccharides.

Glycosidic linkages form between the same locations of monomers giving polymers a standard backbone structure.

From the molecular formula, what would indicate that a six-carbon sugar was a disaccharide composed of two trioses and not a hexose? -In the disaccharide the molecular formula would be C6H12O6. -In the disaccharide the molecular formula would be C6H14O7. -In the disaccharide the molecular formula would be C6H10O5. -There is no way to tell from the molecular formula.

In the disaccharide the molecular formula would be C6H10O5.

Carbohydrates are made up of which of the following subunits? -Nucleotides -Monosaccharides -Free fatty acids -Carbon atoms bonded to water -Amino acids

Monosaccharides

Glycoproteins are important in cell-cell recognition. Where are the carbohydrate portions of these molecules normally found? -On the inside surface of the cell membrane -On the exterior surface of the cell membrane -Embedded in the interior of the cell membrane -In the nucleus of the cells

On the exterior surface of the cell membrane

What is the difference between peptidoglycan, found in the cell walls of prokaryotes, and chitin, found in the exoskeletons of insects? -Parallel strands of glucosamines in chitin are cross-linked by hydrogen bonds, whereas parallel strands of peptidoglycan are linked by peptide bonds. -Chitin has a b-1,4 linkage between its glucosamines, whereas peptidoglycan has an a-1,4 linkage between its constituent glucosamines. -Peptidoglycan is a glucose polymer, whereas chitin is made up of glucosamines. -Chitin is a protein polymer, whereas the peptidoglycan of bacteria is a carbohydrate polymer linked by amino acids.

Parallel strands of glucosamines in chitin are cross-linked by hydrogen bonds, whereas parallel strands of peptidoglycan are linked by peptide bonds.

Simple sugars can differ from one another in which of the following ways? -Some contain hydrogen while others do not. -Carbons in a monosaccharide are attached in a covalent bond known as a glycosidic linkage. -Some have a carbonyl group; others do not. -They can differ in the location of their carbonyl group.

They can differ in the location of their carbonyl group.

If a monosaccharide's carbonyl group is on an internal carbon, then the monosaccharide is ____. -an aldose -a triose -hydrophobic -a ketose

a ketose

The extensive hydrogen bonding found among parallel glucose polymers of cellulose enables it to function in plants as _____. -a transport molecule -a structural polysaccharide -an energy source -a storage polysaccharide

a structural polysaccharide

Sperm identify an ovum by interacting with a glycoprotein called ZP3 in the gelatinous extracellular matrix that surrounds the ovum. Predict the outcome of the experimental removal of sugars from these glycoproteins. When sugars are removed from ZP3, _____. -polyspermy, the fertilization of an egg by multiple sperm, results -the ovum would collapse -the ovum would undergo apoptosis due to a lack of available energy -fertilization is prevented -the ovum is fertilized by one sperm

fertilization is prevented

The predominant form of glucose dissolved in an aqueous solution is _____. -the ketose form -the linear form -the disaccharide form -the ring configuration

the ring configuration

Polysaccharides probably did not play an important role in the origin of life because ____. -they cannot store energy -they do not serve important roles in today's cells -they cannot serve as a template for replication -they lack reactive functional groups

they cannot serve as a template for replication

Monosaccharides differ from one another in ____. -which isotope of carbon they contain -the placement of their amino group -whether they contain an aldose or a ketose group -whether they contain a hydroxyl group

whether they contain an aldose or a ketose group