Chapter 5 MasteringBio

Which of the following is a diverse group of hydrophobic molecules? a) lipids b) carbohydrates c) proteins d) nucleic acids

a) lipids

Which of these is a polysaccharide? a) lactose b) galactose c) cellulose d) sucrose e) glucose

c) cellulose

True or false? Enzymes in the digestive tract catalyze hydrolysis reactions.

True

Which of the following statements about the formation of polypeptides from amino acids is true? a) A bond forms between the carboxyl functional group of one amino acid and the amino functional group of the other amino acid. b) A bond can form between any carbon and nitrogen atom in the two amino acids being joined. c) Polypeptides form by condensation or hydrolysis reactions. d) The reaction occurs through the addition of a water molecule to the amino acids.

a) A bond forms between the carboxyl functional group of one amino acid and the amino functional group of the other amino acid.

What is a triacylglycerol? a) a lipid made with three fatty acids and glycerol b) a molecule formed from three alcohols by dehydration reactions c) a lipid that makes up much of the plasma membrane d) a carbohydrate with three sugars joined together by glycosidic linkages e) a protein with tertiary structure

a) a lipid made with three fatty acids and glycerol

A molecule with the chemical formula C6H12O6 is probably a a) carbohydrate and monosaccharide only. b) monosaccharide c) carbohydrate and lipid only. d) lipid. e) carbohydrate.

a) carbohydrate and monosaccharide only.

Which of these is a source of lactose? a) milk b) sugar beets c) potatoes d) sugar cane e) starch

a) milk

Select the statement that is incorrect. a) Complex sugars are carbohydrates. b) All carbohydrates have the general formula Cn(H2O)n. c) Simple sugars are carbohydrates. d) Simple sugars contain only carbon, oxygen, and hydrogen atoms.

b) All carbohydrates have the general formula Cn(H2O)n.

Which of the following is true of cellulose? a) It is a storage polysaccharide for energy in plant cells. b) It is a major structural component of plant cell walls. c) It is a storage polysaccharide for energy in animal cells. d) It is a major structural component of animal cell plasma membranes. e) It is a polymer composed of sucrose monomers.

b) It is a major structural component of plant cell walls.

Which monomers make up RNA? a) Simple sugars b) Nucleotides c) Amino acids d) Polymers

b) Nucleotides

Which polymers are composed of amino acids? a) Carbohydrates b) Proteins c) Monomers d) Nucleic acids

b) Proteins

All of the following statements concerning saturated fats are true except a) They are one of several factors that contribute to atherosclerosis. b) They have multiple double bonds in the carbon chains of their fatty acids. c) They are more common in animals than in plants. d) They generally solidify at room temperature. e) They contain more hydrogen than unsaturated fats having the same number of carbon atoms.

b) They have multiple double bonds in the carbon chains of their fatty acids.

Glycogen is _____. a) a transport protein that carries oxygen b) a polysaccharide found in animals c) the form in which plants store sugars d) a source of saturated fat e) a polysaccharide found in plant cell walls

b) a polysaccharide found in animals

A function of cholesterol that does not harm health is its role _____. a) the most abundant male sex hormone b) as a component of animal cell membranes c) in calcium and phosphate metabolism d) All of cholesterol's effects cause the body harm. d) as the primary female sex hormone

b) as a component of animal cell membranes

_____ is the most abundant organic compound on Earth. a) Starch b) Glycogen c) Cellulose d) Lactose e) Glucose

c) Cellulose

Which of the following best summarizes the relationship between dehydration reactions and hydrolysis? a) Dehydration reactions can occur only after hydrolysis. b) Macromolecular synthesis occurs through the removal of water and digestion occurs through the addition of water. c) Dehydration reactions assemble polymers, and hydrolysis reactions break down polymers; and macromolecular synthesis occurs through the removal of water and digestion occurs through the addition of water. d) Hydrolysis creates monomers, and dehydration reactions break down polymers.

c) Dehydration reactions assemble polymers, and hydrolysis reactions break down polymers; and macromolecular synthesis occurs through the removal of water and digestion occurs through the addition of water.

Which of the following is true regarding saturated fatty acids? a) They are usually liquid at room temperature. b) They are usually produced by plants. c) They are the principal molecules in lard and butter. d) They have double bonds between carbon atoms of the fatty acids. e) They are the predominant fatty acid in corn oil.

c) They are the principal molecules in lard and butter.

glucose + glucose —> _____ by _____. a) lactose + water ... hydrolysis b) cellulose + water ... hydrolysis c) maltose + water ... dehydration synthesis d) starch + water ... dehydration synthesis e) sucrose + water ... dehydration synthesis

c) maltose + water ... dehydration synthesis

A simple sugar is composed of equal parts carbon and water, which gave rise to the general name of any sugar as a __________________.

carbohydrate

How many molecules of water are needed to completely hydrolyze a polymer that is 11 monomers long? a) 9 b) 8 c) 11 d) 10 e) 12

d) 10

Which of the following is not attached to the central carbon atom in an amino acid? a) A side chain ("R group") b) A carboxyl functional group c) An amino functional group d) An oxygen

d) An oxygen

Which of these is NOT a lipid? a) phospholipid b) wax c) cholesterol d) RNA e) steroids

d) RNA

Why are human sex hormones considered to be lipids? a) They are essential components of cell membranes. b) They contribute to atherosclerosis. c) They are made of fatty acids. d) They are steroids, which are not soluble in water. e) They are hydrophilic compounds.

d) They are steroids, which are not soluble in water.

Lactose, a sugar in milk, is composed of one glucose molecule joined by a glycosidic linkage to one galactose molecule. How is lactose classified? a) as a polysaccharide b) as a hexose c) as a pentose d) as a disaccharide e) as a monosaccharide

d) as a disaccharide

Which of the following polymers contain nitrogen? a) glycogen b) starch c) amylopectin d) chitin e) cellulose

d) chitin

Which of the following is not a polymer? a) starch b) cellulose c) DNA d) glucose e) chitin

d) glucose

All of the following are polysaccharides except a) amylopectin b) chitin c) starch d) lactose e) cellulose

d) lactose

Lactose, the sugar in milk, is a _______________, because it can be split into two monosaccharides.

disaccharide

Which of the following is true of both starch and cellulose? a) They are both structural components of the plant cell wall. b) They are geometric isomers of each other. c) They are both used for energy storage in plants. d) They can both be digested by humans. e) They are both polymers of glucose.

e) They are both polymers of glucose.

On food packages, to what does the term "insoluble fiber" refer? a) amylopectin b) polypeptides c) starch d) chitin e) cellulose

e) cellulose

Humans can digest starch but not cellulose because a) the monomer of starch is glucose, while the monomer of cellulose is galactose. b) humans have enzymes that can hydrolyze the beta (β)c) glycosidic linkages of starch but not the alpha (α) glycosidic linkages of cellulose. c) humans harbor starch-digesting bacteria in the digestive tract. d) the monomer of starch is glucose, while the monomer of cellulose is maltose. e) humans have enzymes that can hydrolyze the alpha (α) glycosidic linkages of starch but not the beta (β) glycosidic linkages of cellulose.

e) humans have enzymes that can hydrolyze the alpha (α) glycosidic linkages of starch but not the beta (β) glycosidic linkages of cellulose.

Which of these is rich in unsaturated fats? a) a fat that is solid at room temperature b) butter c) lard d) beef fat e) olive oil

e) olive oil

A __________________ cannot be hydrolyzed any further.

monosaccharide

A carbohydrate that yields many monosaccharides when hydrolyzed is a ____________________.

polysaccharide