AP Bio Chapter 3

If a DNA sample were composed of 15% adenine, what would be the percentage of thymine? A) 15 B) 30 C) 35 D) 50

A) 15

The side chain (R group) of the amino acid serine is -CH2-OH. The side chain of the amino acid leucine is -CH2-CH-(CH3)2. Where would you expect to find these amino acids in a globular protein in aqueous solution? A) Serine would be on the exterior, and leucine would be in the interior of the globular protein. B) Serine would be in the interior, and leucine would be on the exterior of the globular protein. C) Both serine and leucine would be in the interior of the globular protein. D) Both serine and leucine would be on the exterior of the globular protein.

A) Serine would be on the exterior, and leucine would be in the interior of the globular protein.

Which functional group can act as a base? A) amino B) phosphate C) hydroxyl D) carboxyl E) methyl

A) amino

Which of the following is a monomer used to build a biological polymer? A) amino acid B) disaccharide C) triglyceride D) DNA

A) amino acid

On food packages, to what does the term insoluble fiber refer? A) cellulose B) polypeptides C) starch D) glycogen

A) cellulose

A molecule with the formula C18H36O2 is probably a A) fatty acid. B) carbohydrate. C) hydrocarbon. D) nucleic acid.

A) fatty acid

Which of the following is the smallest carbohydrate? A) lactose B) glycogen C) chitin D) cellulose E) starch

A) lactose

Which of the following chemical equations describes a dehydration reaction? A) monosaccharide + monosaccharide disaccharide + H2O B) monosaccharide + monosaccharide + H2O disaccharide C) disaccharide monosaccharide + monosaccharide + H2O D) disaccharide + H2O monosaccharide + monosaccharide

A) monosaccharide+monosaccharide disaccharide+ H2O

133. The structural level of a protein least affected by a disruption in hydrogen bonding is the A) primary level. B) secondary level. C) tertiary level. D) quaternary level.

A) primary level

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) starch B) cellulose C) chitin D) starch and chitin

A) starch

Large organic molecules are generally synthesized by polymerization of a few types of simple subunits. Which of the following is an exception to this statement? A) a steroid B) cellulose C) DNA D) an enzyme

A) steroid

124. A nutritional supplement developed for athletes is shown to contain only carbon, hydrogen, oxygen, and sulfur. Based on these data, you may safely conclude that A) the food may contain carbohydrates, lipids, and protein. B) the food may contain carbohydrates, lipids, and nucleic acids. C) the food may contain carbohydrates, phospholipids, and protein. D) the food may contain carbohydrates and lipids, but not protein.

A) the food may contain carbohydrates, lipids, and protein.

Which of the following is an example of a dehydration reaction? A) the reaction of two monosaccharides, forming a disaccharide with the release of water B) the reaction of two amino acids, forming a peptide bond with the consumption of water C) the reaction of a fat with glycerol, forming fatty acids with the release of water D) the reaction of a fat, forming glycerol and fatty acids with the release of water

A) the reaction of two monosaccharides, forming a disaccharide with the release of water

Which of the following is true of both starch and cellulose? A) They are both polymers of glucose. B) They are cis-trans isomers of each other. C) They can both be digested by humans. D) They are both used for energy storage in plants. E) They are both structural components of the plant cell wall.

A) they are both polymers of glucose

Which of the following compounds are formed by dehydration reactions? A) triacylglycerols B) monosaccharides C) amino acids D) fatty acids

A) triacyglycerols

When two carbon atoms are joined by a double bond, how many electron pairs are shared between the two carbons? A) 1 B) 2 C) 3 D) 4

B) 2

If one strand of a DNA molecule has the sequence of bases 5'-ATTGCA-3', the other complementary strand would have the sequence A) 5-'TAACGT-3'. B) 5'-TGCAAT-3'. C) 5'-UAACGU-3'. D) 3'-UAACGU-5'.

B) 5'-TGCAAT-3'.

The molecular formula for glucose is C6H12O6. What would be the molecular formula for a molecule made by linking three glucose molecules together by dehydration reactions? A) C18H36O18 B) C18H32O16 C) C6H10O5 D) C18H30O15 E) C16H36O16

B) C18H32O16

136. The molecular formula for glucose is C6H12O6. What would be the molecular formula for a polymer made by linking ten glucose molecules together by dehydration reactions? A) C60H120O60 B) C60H102O51 C) C60H100O50 D) C60H111O51

B) C60H102O51

Hydrogenated vegetable oil is the primary ingredient in margarine. How does hydrogenated vegetable oil differ from nonhydrogenated vegetable oil? A) Hydrogenated vegetable oil has a lower melting point than nonhydrogenated vegetable oil. B) Hydrogenated vegetable oil is solid at room temperature, whereas nonhydrogenated vegetable oil is liquid. C) Hydrogenated vegetable oil has more kinks in its fatty acid chains than does nonhydrogenated vegetable oil. D) Hydrogenated vegetable oil contains more cis fatty acids than nonhydrogenated vegetable oil.

B) Hydrogenated vegetable oil is solid at room temperature, whereas nonhydrogenated vegetable oil is liquid.

Which of the following statements about the 5' end of a polynucleotide strand of RNA is correct? A) The 5' end has a hydroxyl group attached to the number 5 carbon of ribose. B) The 5' end has a phosphate group attached to the number 5 carbon of ribose. C) The 5' end has phosphate attached to the number 5 carbon of the nitrogenous base. D) The 5' end has a nitrogenous base attached to the number 5 carbon of ribose.

B) The 5' end has a phosphate group attached to the number 5 carbon of ribose.

DNase is an enzyme that catalyzes the hydrolysis of the covalent bonds that join nucleotides together. What would first happen to DNA molecules treated with DNase? A) The two strands of the double helix would separate. B) The phosphodiester bonds between deoxyribose sugars would be broken. C) The bases would be separated from the deoxyribose sugars. D) Oxygen atoms would be removed from the deoxyribose sugars.

B) The phosphodiester bonds between deoxyribose sugars would be broken.

134. Enzymes that break down DNA catalyze the hydrolysis of the covalent bonds that join nucleotides together. What would happen to DNA molecules treated with these enzymes? A) The two strands of the double helix would separate. B) The phosphodiester linkages of the polynucleotide backbone would be broken. C) The pyrimidines would be separated from the deoxyribose sugars. D) All bases would be separated from the deoxyribose sugars.

B) The phosphodiester linkages of the polynucleotide backbone would be broken.

Why are the vertebrate sex hormones estradiol and testosterone considered to be lipids? A) They are essential components of cell membranes. B) Their carbon skeletons are composed of primarily C-C and C-H bonds. C) They are made of fatty acids. D) They are hydrophilic compounds.

B) Their carbon skeletons are composed of primarily C-C and C-H bonds.

Changing a single amino acid in a protein consisting of 433 amino acids would A) always alter the primary structure of the protein but never alter its tertiary structure or function. B) always alter the primary structure of the protein and sometimes alter its tertiary structure or function. C) always alter the primary and tertiary structure of the protein but never alter its function. D) sometimes alter the primary and tertiary structure of the protein but always alter its function.

B) always alter the primary structure of the protein and sometimes alter its tertiary structure or function.

Research indicates that ibuprofen, a drug used to relieve inflammation and pain, is a mixture of two enantiomers, that is, molecules that A) have identical chemical formulas but differ in the branching of their carbon skeletons. B) are mirror images of one another. C) exist in either linear chain or ring forms. D) differ in the arrangement of atoms around their double bonds.

B) are mirroring images of one another

Polysaccharides, triacylglycerols, and proteins are similar in that they A) are synthesized from monomers by hydrolysis reactions. B) are synthesized from subunits by dehydration reactions. C) are synthesized through the formation of peptide bonds between monomers. D) are broken down into their subunits by dehydration reactions.

B) are synthesized from subunits by dehydration reactions.

Which of the following classes of biological molecules consist of both small molecules and macromolecular polymers? A) lipids B) carbohydrates C) proteins D) nucleic acids

B) carbohydrates

Which of the following are pyrimidines? A) adenine and thymine B) adenine and guanine C) cytosine and uracil D) cytosine and guanine

B) cytosine and uracile

Which of the following best summarizes the relationship between dehydration reactions and hydrolysis? A) Dehydration reactions split water molecules and add hydroxyl groups to polymers, and hydrolysis reactions remove hydroxyl groups from polymers. B) Dehydration reactions assemble polymers, and hydrolysis reactions break down polymers. C) Dehydration reactions create monomers, and hydrolysis reactions assemble polymers. D) Dehydration reactions break down polymers, and hydrolysis reactions create monomers.

B) dehydration reactions assemble polymers, and hydrolysis reactions break down polymers.

122. A new organism is discovered in the forests of Costa Rica. Scientists there determine that the polypeptide sequence of hemoglobin from the new organism has 72 amino acid differences from humans, 65 differences from a gibbon, 49 differences from a rat, and 5 differences from a frog. These data suggest that the new organism is more closely related to A) humans than to frogs. B) frogs than to humans. C) rats than to frogs. D) humans than to rats. E) gibbons than to rats.

B) frogs than to humans

One of the primary functions of RNA molecules is to A) transmit genetic information to offspring. B) function in the synthesis of proteins. C) make a copy of itself, thus ensuring genetic continuity. D) act as a pattern or blueprint to form DNA.

B) function in the synthesis of proteins

Which of the following are purines? A) cytosine and guanine B) guanine and adenine C) adenine and thymine D) thymine and uracil E) uracil and cytosine

B) guanine and adenine

What maintains the secondary structure of a protein? A) peptide bonds between adjacent amino acids B) hydrogen bonds between the amino group of one peptide bond and the carboxyl group of another peptide bond C) disulfide bonds between the amino group of one peptide bond and the R group of another amino acid D) hydrogen bonds between the carboxyl group of one peptide bond and the R group of another amino acid

B) hydrogen bonds between the amino group of one peptide bond and the carboxyl group of another peptide bond

Which of the following is true of cellulose? A) It is a polymer composed of enantiomers of glucose. B) It is a primary structural component of plant cell walls. C) It is digestible by bacteria in the human gut. D) It is a storage polysaccharide for energy in plant cells. E) It is a polymer of glucose joined by α glycosidic linkages.

B) it is a primary structural component of plant cell walls.

Which of the following functional groups is hydrophobic? A) amino B) methyl C) carboxyl D) hydroxyl

B) methyl

If cells are grown in a medium containing radioactive 32P, which of these molecules will be radioactively labeled? A) triacylglycerols B) nucleic acids C) fatty acids D) starch

B) nucleic acids

In a normal cellular protein, where would you expect to find a hydrophilic amino acid such as asparagine? A) in the interior of the folded protein, away from water B) on the exterior surface of the protein, interacting with water C) in the transmembrane portion interacting with lipid fatty acid chains D) on the exterior surface of the protein, interacting with water, or in a transmembrane portion interacting with lipid fatty acid chains

B) on the exterior surface of the protein, interacting with water

Which of the following will dissolve in water? A) organic hydrocarbons B) organic molecules with hydroxyl groups C) carbon skeletons bound to hydrogen D) fats

B) organic molecules with hydroxyl groups

How will brief heating (to 95°C) affect macromolecular structures in aqueous solution? A) Unsaturated fatty acid tails will become saturated. B) Proteins will unfold (denature). C) Starch will hydrolyze into monomeric sugars. D) Proteins will hydrolyze into amino acids.

B) proteins will unfold (denature)

The α helix and β pleated sheet are examples of which level of protein structure? A) primary B) secondary C) tertiary D) quaternary E) primary, secondary, tertiary, and quaternary

B) secondary

Collagen is a protein made of three identical polypeptides composed primarily of α helix structure. The α helix is an example of A) secondary structure stabilized by covalent bonds. B) secondary structure stabilized by hydrogen bonds. C) secondary structure stabilized by ionic bonds. D) tertiary structure stabilized by covalent bonds. E) tertiary structure stabilized by hydrogen bonds.

B) secondary structure stabilized by hydrogen bonds

125. A nutritional supplement developed for athletes is shown to contain only carbon, hydrogen, nitrogen, and oxygen. Based on these data, you may safely conclude that A) the food does not contain protein. B) the food does not contain nucleic acids. C) the food does not contain carbohydrates. D) the food does not contain lipids.

B) the food does not contain nucleic acids

Why are hydrocarbons insoluble in water? A) The majority of their bonds are polar covalent carbon-to-hydrogen linkages. B) The majority of their bonds are nonpolar covalent carbon-to-hydrogen linkages. C) They are hydrophilic. D) They exhibit considerable molecular complexity and diversity.

B) the majority of their bonds are nonpolar covalent carbon-to-hydrogen linkages.

132. Which of the following statements concerning unsaturated fats is true? A) They are more common in animals than in plants. B) They have double bonds in their fatty acid chains. C) They generally solidify at room temperature. D) They contain more hydrogen than do saturated fats having the same number of carbon atoms.

B) they have double bonds in their fatty acid chains.

121. Approximately 32 different monomeric carbohydrate subunits are found in various natural polysaccharides. Proteins are composed of 20 different amino acids. DNA and RNA are each synthesized from four nucleotides. Which class of biological polymer has the greatest functional variety? A) polysaccharides B) proteins C) DNA D) RNA

B. proteins

If a DNA sample were composed of 15% adenine, what would be the percentage of guanine? A) 15 B) 30 C) 35 D) 50

C) 35

135. Which of the following hydrocarbons has a double bond in its carbon skeleton? A) C3H8 B) C2H6 C) C2H4 D) C2H2

C) C2H4

Which of the following statements regarding saturated fatty acids is true? A) They are the predominant fatty acid in corn oil. B) They have double bonds between the carbon atoms of the fatty acids. C) They are the principal molecules in lard and butter. D) They are usually liquid at room temperature. E) They are usually produced by plants.

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

A nucleotide is composed of A) a nitrogenous base and a phosphate group. B) a nitrogenous base and a pentose sugar. C) a nitrogenous base, a phosphate group, and a pentose sugar. D) a nitrogenous base, a phosphate group, a pentose sugar, and an amino acid.

C) a nitrogenous base, a phosphate group, and a pentose sugar.

130. Which chemical group is most likely to be responsible for an organic molecule behaving as a base (see Concept 2.5)? A) hydroxyl B) carbonyl C) amino D) phosphate

C) amino

Which of the following is a correct monomer/polymer pairing? A) monosaccharide/polypeptide B) amino acid/polysaccharide C) amino acid/polypeptide D) glycerol/triglyceride

C) amino acid/ polypeptide

131. Which of the following categories includes all others in the list? A) disaccharide B) starch C) carbohydrate D) polysaccharide

C) carbohydrate

Amino acids are acids because they always possess which functional group? A) amino B) carbonyl C) carboxyl D) phosphate E) hydroxyl

C) carboxyl

A carbon atom is most likely to form which of the following bonds with other atoms? A) ionic bonds B) hydrogen bonds C) covalent bonds D) covalent bonds and hydrogen bonds

C) covalent bonds

What is a common chemical reaction mechanism by which cells make polymers from monomers? A) decreasing the pH B) hydrolysis reactions C) dehydration reactions D) the formation of disulfide bridges between monomers

C) dehydration reaction

There are 20 different amino acids. What makes one amino acid different from another? A) different side chains (R groups) attached to the carboxyl carbon B) different side chains (R groups) attached to the amino groups C) different side chains (R groups) attached to an α carbon D) different asymmetric carbons

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

The sequence 5'- GAACGA'3' may be found in which of the following? A) DNA only B) RNA only C) either DNA or RNA D) neither DNA nor RNA

C) either DNA or RNA

Which of the following polymers lacks nitrogen? A) protein B) RNA C) glycogen D) chitin

C) glycogen

126. A scientist suspects that food in an ecosystem may have been contaminated by radioactive nitrogen over a period of several months. Which of the following should be isolated from mammals living in the ecosystem and examined for radioactivity in order to test the hypothesis? A) glycogen B) DNA C) hair D) fat

C) hair

Humans can digest starch but not cellulose because A) the monomer of starch is glucose, whereas the monomer of cellulose is glucose modified by the addition of a nitrogen-containing group. B) humans have enzymes that can hydrolyze the β glycosidic linkages of starch but not the α glycosidic linkages of cellulose. C) humans have enzymes that can hydrolyze the α glycosidic linkages of starch but not the β glycosidic linkages of cellulose. D) humans harbor starch-digesting bacteria in the digestive tract, but not cellulose-digesting bacteria.

C) humans have enzymes that can hydrolyze the α glycosidic linkages of starch but not the β glycosidic linkages of cellulose.

Which type of interaction stabilizes the α helix and the β pleated sheet structures of proteins? A) hydrophobic interactions B) ionic bonds C) hydrogen bonds D) peptide bonds

C) hydrogen bonds

A molecule with the chemical formula C6H12O6 is probably a A) hydrocarbon. B) lipid. C) monosaccharide D) glycerol.

C) monosaccharide

The tertiary structure of a polypeptide is the A) linear sequence of amino acids in a polypeptide. B) localized region of a polypeptide chain that forms an α helix or β pleated sheet. C) overall three-dimensional shape of a fully folded polypeptide. D) overall three-dimensional shape of a protein composed of more than one polypeptide.

C) overall three-dimensional shape of a fully folded polypeptide.

Which bonds are created during the formation of the primary structure of a protein? A) disulfide bonds B) hydrogen bonds C) peptide bonds D) phosphodiester bonds

C) peptide bonds

If cells are grown in a medium containing radioactive 35S, which of these molecules will be radioactively labeled? A) phospholipids B) nucleic acids C) proteins D) starch

C) proteins

1) Figure 3.1 The two molecules shown in Figure 3.1 are best described as A) optical isomers. B) enantiomers. C) structural isomers. D) cis-trans isomers.

C) structural isomers

Interactions between the side chains (R groups) in a polypeptide are most important in stabilizing which of the following? A) primary structure B) secondary structure C) tertiary structure D) quaternary structure

C) tertiary structure

Testosterone and estradiol are male and female sex hormones, respectively, in many vertebrates. How do these molecules differ from each other? A) Testosterone and estradiol are structural isomers but have the same molecular formula. B) Testosterone and estradiol are cis-trans isomers but have the same molecular formula. C) Testosterone and estradiol have different functional groups attached to the same carbon skeleton. D) Testosterone and estradiol are enantiomers of the same organic molecule.

C) testosterone and estradiol have different functional groups attached to the same carbon skeleton

When carbon forms single covalent bonds with four other atoms, the atoms joined to the carbon form a A) sphere. B) cube. C) tetrahedron. D) line. E) plane

C) tetrahedron

Which of the following will result in changing the orientation of bonds between carbon and other atoms from a tetrahedral configuration to a planar configuration? A) the presence of single covalent bonds with oxygen atoms B) the presence of single covalent bonds with nitrogen atoms C) the presence of double covalent bonds between the carbon atom and other atoms D) the presence of polar covalent bonds between carbon and other atoms

C) the presence of double covalent bonds between the carbon atom and other atoms

Lactase is an enzyme composed of a single polypeptide that hydrolyzes the disaccharide lactose to produce monosaccharides. The optimal pH for lactase activity is 6. Transfer of lactase to pH 5 results in a substantial decrease in enzyme activity, likely due to the disruption of A) only the primary structure of the enzyme. B) the primary and secondary structure of the enzyme. C) the secondary and tertiary structure of the enzyme. D) the secondary, tertiary, and quaternary structure of the enzyme.

C) the secondary and tertiary structure of the enzyme.

Which of the following statements concerning saturated fats is true? A) They are more common in plants than in animals. B) They have multiple double bonds in the carbon chains of their fatty acids. C) They are generally solid at room temperature. D) They contain fewer hydrogen atoms than unsaturated fats having the same number of carbon atoms.

C) they are generally solid at room temperature.

A carbon skeleton is covalently bonded to both an amino group and a carboxyl group. When placed in water, it A) will function only as an acid because of the carboxyl group. B) will function only as a base because of the amino group. C) will function as both an acid and a base. D) will function as neither an acid nor a base.

C)will function as both an acid and a base

A double-stranded DNA molecule contains a total of 120 purines and 120 pyrimidines. This DNA molecule could be composed of A) 120 adenine and 120 uracil molecules. B) 120 adenine and 120 guanine molecules. C) 120 cytosine and 120 thymine molecules. D) 120 thymine and 120 adenine molecules.

D) 120 thymine and 120 adenine molecules.

How many electron pairs does carbon share in order to complete its valence shell? A) 1 B) 2 C) 3 D) 4 E) 8

D) 4

) How many peptide bonds are present in a polypeptide that contains 45 amino acids? A) 90 B) 46 C) 45 D) 44

D) 44

How many molecules of water are needed to completely hydrolyze a polysaccharide that is 10 monomers long? A) 12 B) 11 C) 10 D) 9

D) 9

Which of the following polymers contains nitrogen? A) starch B) glycogen C) cellulose D) chitin

D) Chitin

If 14C-labeled uracil is added to the growth medium of cells, what macromolecules will be labeled? A) polysaccharides B) proteins C) DNA D) RNA E) both DNA and RNA

D) RNA

127. A food company wishes to convert corn oil into a spread that is solid at room temperature. One way to accomplish this goal would be to A) remove hydrogens, increasing the number of double bonds in the oil molecules. B) remove hydrogens, decreasing the number of double bonds in the oil molecules. C) add hydrogens, increasing the number of double bonds in the oil molecules. D) add hydrogens, decreasing the number of double bonds in the oil molecules.

D) add hydrogens, decreasing the number of double bonds in the oil molecules

120. A chemist wishes to make an organic molecule less acidic. Which of the following functional groups should be added to the molecule in order to do so? A) carboxyl B) sulfhydryl C) hydroxyl D) amino E) phosphate

D) amino

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 pentose B) as a hexose C) as a monosaccharide D) as a disaccharide E) as a polysaccharide

D) as a disaccharide

2) Figure 3.2 What is the name of the functional group shown in Figure 3.2? A) carbonyl B) ketone C) aldehyde D) carboxyl E) hydroxyl

D) carboxyl

Which two functional groups are always found in amino acids? A) hydroxyl and carboxyl B) carbonyl and amino C) ketone and amino D) carboxyl and amino

D) carboxyl and amino

The difference between the sugar in DNA and the sugar in RNA is that the sugar in DNA A) is a six-carbon sugar and the sugar in RNA is a five-carbon sugar. B) is a five-carbon sugar and the sugar in RNA is a six-carbon sugar. C) is in the α configuration and the sugar in RNA is in the β configuration. D) contains one less oxygen atom than the sugar in RNA.

D) contains one less oxygen atom than the sugar in RNA.

A disulfide bridge is an example of which type of bond? A) ionic bond between R groups B) hydrophobic interaction between R groups C) hydrogen bond between R groups D) covalent bond between R groups

D) covalent bond between R groups

Which of the following chemical equations describes a hydrolysis reaction? A) monosaccharide + monosaccharide disaccharide + H2O B) monosaccharide + monosaccharide + H2O disaccharide C) disaccharide monosaccharide + monosaccharide + H2O D) disaccharide + H2O monosaccharide + monosaccharide

D) disaccharide+H2O monosaccharide+ monosaccharide

Which of the following functional groups may be used to form polymers via dehydration reactions? A) only hydroxyl groups B) only carbonyl groups C) only carboxyl groups D) either hydroxyl or carboxyl groups E) either carbonyl or carboxyl groups

D) either hydroxyl or carboxyl groups

The primary functional groups in a common macromolecule are hydroxyl groups. Which of the following statements regarding this macromolecule is true? A) It lacks an asymmetric carbon, and it is probably a fat or lipid. B) It will not dissolve in water. C) It will dissolve in a nonpolar solvent. D) It will form hydrogen bonds with water.

D) it will form hydrogen bonds with water

The sequence 5'-GAACUT-3' may be found in which of the following? A) DNA only B) RNA only C) either DNA or RNA D) neither DNA nor RNA

D) neither DNA nor RNA

Which bonds maintain the primary structure of a protein? A) disulfide bonds B) hydrogen bonds C) ionic bonds D) peptide bonds

D) peptide bonds

Which of the following large biological molecules will self-assemble into a bilayer when mixed with water? A) proteins B) triacylglycerols C) cellulose D) phospholipids

D) phospholipids

123. A nutritional supplement developed for athletes is shown to contain only carbon, hydrogen, and oxygen. Based on these data, you may safely conclude that A) the food may contain carbohydrates and protein. B) the food may contain carbohydrates and nucleic acids. C) the food may contain lipids and protein. D) the food may contain carbohydrates and lipids, but not protein.

D) the food may contain carbohydrates and lipids, but not protein

Which of the following is an example of a hydrolysis reaction? A) the reaction of two monosaccharides, forming a disaccharide with the release of water B) the synthesis of two amino acids, forming a peptide bond with the release of water C) the reaction of a fat with glycerol, forming fatty acids with the release of water D) the reaction of a fat, forming glycerol and fatty acids with the consumption of water

D) the reaction of a fart, forming glycerol and fatty acids with the consumption of water

The biochemical reaction that joins two amino acids to form a dipeptide is accompanied by 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.

D) the release of a water molecule

Which of the following statements regarding lipids is true? A) They generally contain nitrogen. B) They are made from glycerol and amino acids. C) A gram of lipid stores less energy than a gram of carbohydrate. D) They are insoluble in water.

D) they are insoluble in water.

When two carbon atoms are joined by a double bond, the atoms joined to the carbons form a A) sphere. B) cube. C) tetrahedron. D) line. E) plane.

E) Plane

Normal hemoglobin is a tetramer, consisting of two molecules of β-globin and two molecules of α-globin. In sickle-cell disease, as a result of a single amino acid change, the mutant hemoglobin tetramers associate with each other and assemble into large fibers. Based on this information alone, we can conclude that sickle-cell hemoglobin exhibits A) altered primary structure. B) altered secondary structure. C) altered tertiary structure. D) altered quaternary structure. E) altered primary structure and altered quaternary structure; the secondary and tertiary structures may or may not be altered.

E) altered primary structure and altered quaternary structure; the secondary and tertiary structures may or may not be altered.

If cells are grown in a medium containing radioactive 15N, which of these molecules will be labeled? A) fatty acids only B) nucleic acids only C) proteins only D) both fatty acids and proteins E) both proteins and nucleic acids

E) both proteins and nucleic acids

Which of the following molecules lacks amino acids? A) hemoglobin B) insulin C) antibodies D) spider silk E) cholesterol

E) cholesterol