Chapter 4 MasteringBio

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

a) 10

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

a) Cellulose

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

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

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

a) cellulose

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

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

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

a) maltose + water ... dehydration synthesis

The tertiary structure of a protein is the a) unique three-dimensional shape of the fully folded polypeptide. b) organization of a polypeptide chain into an α helix or β pleated sheet. c) order in which amino acids are joined in a polypeptide chain. d) overall protein structure resulting from the aggregation of two or more polypeptide subunits. e) bonding together of several polypeptide chains by weak bonds.

a) unique three-dimensional shape of the fully folded polypeptide.

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

b) RNA

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

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

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

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

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

b) a lipid made with three fatty acids and glycerol

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

b) chitin

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

b) milk

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

b) olive oil

Which bonds are created during the formation of the primary structure of a protein? a) peptide bonds, hydrogen bonds, and disulfide bonds b) peptide bonds c) phosphodiester bonds d) hydrogen bonds e) disulfide bonds

b) peptide bonds

Enzymes are a) lipids. b) proteins. c) carbohydrates. d) nucleic acids.

b) proteins.

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

c) as a component of animal cell membranes

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 monosaccharide b) as a polysaccharide c) as a disaccharide d) as a hexose e) as a pentose

c) as a disaccharide

The function of each protein is a consequence of its specific shape. What is the term used for a change in a protein's three-dimensional shape or conformation due to disruption of hydrogen bonds, disulfide bridges, or ionic bonds? a) stabilization b) renaturation c) denaturation d) hydrolysis e) destabilization

c) denaturation

There are 20 different amino acids. What makes one amino acid different from another? a) different alpha (α) carbons b) different carboxyl groups attached to an alpha (α) carbon c) different side chains (R groups) attached to an alpha (α) carbon d) different amino groups attached to an alpha (α) carbon e) different asymmetric carbons

c) different side chains (R groups) attached to an alpha (α) carbon

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

c) glucose

The element nitrogen is present in all of the following except a) amino acids. b) DNA. c) monosaccharides. d) nucleic acids. e) proteins.

c) monosaccharides.

Upon chemical analysis, a particular polypeptide was found to contain 100 amino acids. How many peptide bonds are present in this protein? a) 98 b) 101 c) 100 d) 99 e) 97

d) 99

Polysaccharides, nucleic acids, and proteins are similar in that they a) are synthesized as a result of peptide bond formation between monomers. b) are decomposed into their subunits by dehydration reactions. c) all contain nitrogen in their monomer building blocks. d) are synthesized by dehydration reactions. e) are synthesized from monomers by the process of hydrolysis.

d) are synthesized by dehydration reactions.

What is the chemical mechanism by which cells make polymers from monomers? a) phosphodiester linkages b) hydrolysis c) the formation of disulfide bridges between monomers d) dehydration reactions e) ionic bonding of monomers

d) dehydration reactions

The enzyme amylase can break glycosidic linkages between glucose monomers only if the monomers are the α form. Which of the following could amylase break down? a) chitin b) glycogen and cellulose only c) glycogen, cellulose, and chitin d) glycogen e) cellulose

d) glycogen

What maintains the secondary structure of a protein? a) ionic bonds b) disulfide bonds c) phosphodiester bonds d) hydrogen bonds e) peptide bonds

d) hydrogen bonds

The α helix and the β pleated sheet are both common polypeptide forms found in which level of protein structure? a) tertiary b) quaternary c) primary d) secondary e )all of the above

d) secondary

The bonding of two amino acid molecules to form a larger molecule requires a) the addition of a water molecule. b) the release of a carbon dioxide molecule. c) the addition of a nitrogen atom. d) the release of a water molecule. e) both the release of a carbon dioxide molecule and the addition of a nitrogen atom.

d) the release of a water molecule.

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

e) a polysaccharide found in animals

All of the following contain amino acids except a) insulin. b) hemoglobin. c) antibodies. d) enzymes. e) cholesterol

e) cholesterol