CHAPTER 16 BIOCHEMISTRY
39) The bond between two amino acids is called a peptide bond. What type of bond is a peptide bond? A) amide B) anhydride C) amine D) glyceride
a
4) Cell nutrients and waste must pass through the cell A) membrane. B) nucleus. C) ribosomes. D) chloroplasts.
a
41) A relatively small molecule with more than 10 amino acids is called a A) polypeptide. B) protein. C) polysaccharide. D) polynucleic acid.
a
11) From an organic chemistry perspective, carbohydrates are polyhydroxy A) carboxylic acids. B) aldehydes and ketones. C) amines. D) amino acids.
b
19) The molecular formula for glucose is A) C12H6O6. B) C6H12O6. C) C6H6O12. D) C12H22O11.
b
21) Unsaturated fats are often liquids called A) hydrogenated fats. B) oils. C) triglycerides. D) glycerol.
b
22) A fatty acid is determined to have 12 carbon atoms. This fatty acid is probably from a(n) A) synthetic source. B) natural source. C) plant. D) animal.
b
31) The mass of iodine that is consumed by 100 g of a fat or oil is known as the A) fat replacement number. B) iodine number. C) oil replacement number. D) saturation number.
b
1) The genetic information of a cell is found in the chloroplasts.
f
10) Changing one amino acid in a protein sequence will always have a negative effect.
f
11) The great diversity of proteins is due to the large number of amino acids from which proteins are made.
f
13) All proteins exhibit primary, secondary, tertiary and quaternary structure.
f
16) Worldwide production of enzymes is worth more than $20 billion per year.
f
17) A nucleotide made up of cytosine, ribose and a phosphate would be found in DNA.
f
19) In a sample of DNA, the amount of A will be equal to the amount of G.
f
23) The molecule that carries the amino acid to the site of protein synthesis is mRNA.
f
26) Gene therapy has been widely used in treating people who have a genetic disease.
f
3) Chloroplasts convert light energy into heat energy.
f
4) The main difference between starch and glycogen is that starch has alpha (α) linkages between glucose units while glycogen has beta (β) linkages.
f
5) Cellulose and starch are made up of glucose monomers, so they can both be digested by humans.
f
6) Naturally occurring fatty acids usually have an odd number of carbons.
f
9) An amino acid has an amide group and a carboxyl acid group.
f
29) A compound that has two fatty acids joined to a glycerol molecule by ester linkages is a(n) A) diglyceride. B) fat. C) oil. D) triglyceride.
a
3) In cells, primary energy production occurs in the A) mitochondria. B) nucleus. C) ribosomes. D) cell membrane.
a
30) Which of the following would have the lowest iodine number? A) butter B) corn oil C) peanut oil D) sunflower oil
a
38) Proteins are A) polyamides. B) polysaccharides. C) polysulfides. D) polyamines.
a
12) Which of the following is a monosaccharide? A) fructose B) sucrose C) starch D) amylose
a
13) The polysaccharide that is in potatoes and cereal grains is A) starch. B) galactose. C) cellulose. D) fructose.
a
17) An example of a disaccharide is A) sucrose. B) galactose. C) dextrose. D) cellulose.
a
25) Fats and oils are differentiated from each other on the basis of their A) melting points. B) densities. C) glycerol content. D) boiling points.
a
27) Animal fats are A) solids and have a smaller proportion of unsaturated fats. B) solids and have a higher proportion of unsaturated fats. C) liquids and have a higher proportion of unsaturated fats. D) liquids and have a smaller proportion of unsaturated fats.
a
28) The iodine numbers for several samples of fatty acids are shown below. Which fatty acid is the most saturated? A) 40 (Fatty Acid A) B) 80 (Fatty Acid B) C) 105 (Fatty Acid C) D) 135 (Fatty Acid D)
a
48) Certain side chains (R groups) in amino acids are nonpolar. In the structure of a protein, nonpolar groups are generally found A) on the interior of the protein structure, shielded from interaction with water molecules. B) on the exterior of the protein structure, shielded from interaction with water molecules. C) on the interior of the protein structure, maximizing their interaction with water molecules. D) on the exterior of the protein structure, maximizing their interaction with water molecules.
a
49) An alpha helix contains A) intramolecular hydrogen bonding. B) intermolecular hydrogen bonding. C) ester formation within the chain. D) ether formation within the chain.
a
51) Which of the following forces is NOT involved in the determining the structure of proteins? A) base pairing B) disulfide linkages C) dispersion forces D) hydrogen bonds
a
53) Which of the following is NOT involved in determining the tertiary structure of a protein? A) ester bonds B) salt bridges C) disulfide linkages D) hydrogen bonds
a
55) A coenzyme may be an ion such as A) Mg2+. B) Cl-. C) O2-. D) K+.
a
56) Extremophiles are microorganisms that A) live in harsh environments that would kill other creatures. B) live outside the body. C) live in the water supply. D) live in thick forests.
a
57) Enzymes are A) catalysts. B) structural material. C) genetic material. D) nucleic acids.
a
59) The portion of an enzyme where the substrate "fits" during the reaction is called the A) active site. B) action site. C) reaction site. D) substrate site.
a
6) The primary chemical for the storage of energy in plants is A) carbohydrate. B) protein. C) cellulose. D) nucleic acid.
a
66) Nucleotides in nucleic acids are joined by links through the A) phosphate groups. B) base groups. C) sugar groups. D) peptide bonds.
a
72) Which of the following statements comparing DNA and RNA is correct? A) DNA exists as a double helix of DNA chains; RNA is single stranded. B) RNA exists as a double helix of RNA chains; DNA is single stranded. C) Both DNA and RNA exist as a double helix. D) Both DNA and RNA are single stranded.
a
74) Which of the following is NOT true for a DNA double helix? A) Complementary base pairs are on the outside of the double helix. B) Complementary base pairs are on the inside of the double helix. C) The phosphate groups are on the outside of the double helix. D) Each complementary base pair contains a pyrimidine and a purine.
a
76) DNA is found primarily in the cell A) nucleus. B) ribosomes. C) mitochondria. D) DNA is found throughout the cell.
a
77) The hereditary material of all cells is found in the A) chromosomes. B) mitochondria. C) ribosomes. D) cytoplasm.
a
79) If the DNA template chain contains the 5' → 3' sequence A-T-T-G-C, what will be the sequence on the newly synthesized DNA chain? A) 3' → 5' T-A-A-C-G B) 5' → 3' T-A-A-C-G C) 3' → 5' U-A-A-C-G D) 5' → 3' U-A-A-C-G
a
8) The series of chemical reactions that synthesize molecules for use by a living system is called A) anabolism. B) catabolism. C) biobolism. D) metabolism.
a
88) What is the complementary RNA base for the DNA base of adenine? A) uracil B) cytosine C) adenine D) valine
a
89) Which of the following statements about the genetic code is NOT true? A) Each codon consists of four bases. B) An amino acid may be coded for by more than one codon. C) Some codons act as stop signals and terminate further synthesis of a protein chain. D) Codons consist of some combination of A, G, C and U.
a
91) The bacterial DNA that is used as the splice receptor in recombinant DNA is called a A) plasmid. B) codon. C) clones. D) restrictor.
a
34) Which of the following statements about essential amino acids is NOT correct? A) Essential amino acids cannot be synthesized by the human body. B) Essential amino acids cannot be incorporated into protein. C) Essential amino acids must be part of the diet. D) Some amino acids are essential for infants and children, but not for adults.
b
36) Using biochemical methods to make products has many advantages over more traditional methods. Which of the following is NOT an advantage of biochemical methods? A) Reactions frequently use water as a solvent, and water is nontoxic and nonflammable. B) Nonpolar products are difficult to separate from a water solvent. C) Most biochemical reactions are carried out at mild temperatures and atmospheric pressure. D) Enzymes can be used repeatedly to catalyze the formation of many molecules and thus generate little waste.
b
42) The primary structure of a protein is determined by A) the amino acid composition. B) the order of amino acids in the protein. C) the hydrogen bonding that gives the protein three dimensional shape. D) the intertwining of protein molecules to form a "functional" protein.
b
44) The helical structure of certain proteins, such as wool, is part of the protein's A) primary structure. B) secondary structure. C) tertiary structure. D) quaternary structure.
b
45) The pleated structure of certain proteins, such as silk, is part of the protein's A) primary structure. B) secondary structure. C) tertiary structure. D) quaternary structure.
b
47) A disulfide linkage in a protein is a(n) A) ionic bond between sulfur atoms on different amino acids. B) covalent bond between sulfur atoms on different amino acids. C) hydrogen bond between sulfur atoms on different amino acids. D) hydrophobic interaction between sulfur atoms on different amino acids.
b
50) A beta pleated sheet A) contains ester bonds between chains. B) contains hydrogen bonding between chains. C) contains amide bonds between chains. D) contains ether bonds between chains.
b
52) The interactions between different chains in a protein contribute to its ________ structure. A) primary B) quaternary C) secondary D) tertiary
b
54) Which of the following involves the formation of a covalent bond? A) dispersion forces B) disulfide linkages C) hydrogen bonding D) salt bridges
b
60) An organic molecule that must bind to an enzyme to make it function properly is a(n) A) apoenzyme. B) coenzyme. C) extremophile. D) isomerase.
b
70) Watson and Crick proposed that DNA exists as a(n) A) alpha helix. B) double helix. C) beta sheet. D) pleated sheet.
b
71) Base pairing in DNA occurs through A) covalent bonds between complementary bases on nucleic acid chains. B) hydrogen bonds between complementary bases on nucleic acid chains. C) salt bonds between complementary bases on nucleic acid chains. D) an interaction that is not well understood.
b
73) Which of the following is NOT found in nucleic acids? A) deoxyribose B) glycerol C) phosphate D) thymine
b
75) Which of the following base pairs is NOT found in DNA? A) C-G B) T-C C) A-T D) None of the above
b
80) The first step in protein synthesis in cells is A) replication. B) transcription. C) translation. D) destruction.
b
82) What type of molecule carries the amino acid from the cell fluid to the ribosomes? A) uracil B) tRNA C) guanine D) DNA
b
9) The process in which molecules are degraded to provide energy is known as A) anabolism. B) catabolism. C) energism. D) metabolism.
b
14) Which of the following is a polysaccharide? A) erythrulose B) fructose C) starch D) maltose
c
18) The name carbohydrate reflects A) the ratio of carbon to hydrogen in the molecule. B) the ratio of carbonyl groups to total carbon content. C) the ratio of carbon to the combined ratio of "hydrogen to oxygen." D) the ratio of carbon to oxygen.
c
2) In cells, protein synthesis occurs on the A) nucleus. B) mitochondria. C) ribosomes. D) cytoplasm.
c
35) The materials used in biochemical production of molecules A) tend to be toxic, even at low concentrations. B) are difficult to degrade. C) work well under mild temperature conditions. D) result in large amounts of waste being produced.
c
43) The secondary structure of a protein is determined by A) the amino acid composition. B) the order of amino acids in the protein. C) the hydrogen bonding between atoms in peptide bonds that gives the protein a three dimensional shape. D) the intertwining of protein molecules to form a "functional" protein.
c
46) Disulfide linkages in proteins are formed when two units of ________ are oxidized to form a covalent bond. A) valine B) threonine C) cysteine D) asparagine
c
5) Chloroplasts in plants convert A) light energy into heat energy. B) light energy into electrical energy. C) light energy into chemical energy. D) heat energy into chemical energy.
c
63) The repeating units in both DNA and RNA are called A) monomers. B) nucleic acids. C) nucleotides. D) amino acids.
c
65) The sugar in the nucleotides of RNA is A) glucose. B) lactose. C) ribose. D) sucrose.
c
67) One of the bases in the nucleotides of DNA is A) lactose. B) deoxyribose. C) adenine. D) uracil.
c
68) The most important feature that distinguishes one DNA molecule from another is (are) A) the type of phosphate bonds. B) the type of sugar in each molecule. C) the order of the bases attached to the sugar phosphate backbone. D) all of the above features
c
78) Human body cells have ________ chromosomes. A) 52 B) 22 C) 46 D) 14
c
81) Transcription is the process by which DNA passes information to A) another strand of DNA. B) transfer RNA. C) messenger RNA. D) a new cell.
c
86) The process in which mRNA is made from DNA is A) complementation. B) replication. C) transcription. D) translation.
c
87) If the DNA template chain contains the 5' → 3' sequence A-T-T-G-C, what will be the sequence on the newly synthesized mRNA chain? A) 3' → 5' T-A-A-C-G B) 5' → 3' T-A-A-C-G C) 3' → 5' U-A-A-C-G D) 5' → 3' U-A-A-C-G
c
90) The class of compounds that serve as the source of information and control in living systems are A) amino acids. B) carbohydrates. C) nucleic acids. D) proteins.
c
92) Identify the example that is NOT an example of recombinant DNA technology. A) erythropoietin B) factor VIII C) chromatograph D) recombinant vaccines
c
1) The substructures that distinguish plant and animal cells are A) ribosomes. B) nuclei. C) mitochondria. D) chloroplasts.
d
10) Which of the following elements is NOT found in carbohydrates? A) hydrogen B) oxygen C) carbon D) sulfur
d
15) The monomer unit in amylopectin is ________. A) glucose B) mannose C) lactose D) sucrose
d
16) Animal starch is called A) amylose. B) amylopectin. C) cellulose. D) glycogen.
d
20) Which of the following polymers is NOT made by plants? A) amylopectin B) amylose C) cellulose D) glycogen
d
23) Iodine number is a measure of A) the number of iodine atoms in a carbohydrate. B) the number of iodine atoms in a fat. C) the number of iodine atoms in a protein. D) the degree of unsaturation of a fat.
d
24) Fats and oils are examples of A) ketones. B) aldehydes. C) alcohols. D) esters.
d
26) Triglyceride is another term for A) cholesterol. B) protein. C) blood sugar. D) a fat or oil.
d
32) What functional group(s) is (are) contained in an amino acid? A) -NH2 B) -C=O C) -COOH D) both -NH2 and -COOH
d
33) What is a zwitterion? A) a compound that carries two positively charged atoms B) a compound that carries two negatively charged atoms C) a compound that carries either two positively charged atoms or two negatively charged atoms D) a compound that carries one positively charged atom and one negatively charged atom
d
37) Which of the following approaches has NOT been explored as an alternate source of gasoline? A) Transformation of plant carbohydrates to form gasoline. B) Engineering bacteria that can convert carbohydrates and carbon dioxide into gasoline. C) Development of bacteria that produce hydrocarbon fuels. D) All of the above have been explored as alternate sources of gasoline.
d
40) How many different tripeptides can be made that contain serine, glycine and phenylalanine? A) 1 B) 2 C) 3 D) 6
d
58) Which of the following statements BEST describes the action of enzymes in living systems? A specific enzyme generally catalyzes A) one specific reaction. B) a group of similar reactions. C) many different reactions. D) either one specific reaction or a group of similar reactions.
d
61) A substance that is acted upon by an enzyme and undergoes a change is knows as a(n) A) cofactor. B) coenzyme. C) essential amino acid. D) substrate.
d
62) RNA is found A) primarily in the cell nucleus. B) primarily in cell ribosomes. C) primarily in cell mitochondria. D) in all parts of the cell.
d
64) The sugar in the nucleotides of DNA is A) glucose. B) lactose. C) sucrose. D) deoxyribose.
d
69) One of the bases in the nucleotides of RNA is A) fructose. B) deoxyribose. C) thymine. D) cytosine.
d
7) The series of chemical reactions that keep living organisms alive is referred to as A) anabolism. B) catabolism. C) biobolism. D) metabolism.
d
83) Which molecule is made in the translation process? A) DNA B) mRNA C) rRNA D) protein
d
84) Which of the following bases is found in RNA but not in DNA? A) adenine B) cytosine C) guanine D) uracil
d
85) The process in which proteins are made from mRNA is A) complementation. B) replication. C) transcription. D) translation.
d
93) Recombinant DNA A) contains DNA from different cells of the same organism. B) contains DNA from several different organisms. C) contains DNA from one organism, but some of the original DNA has been deleted. D) contains DNA from two different organisms.
d
12) A salt bridge occurs when the oppositely charged side chains on two amino acids within the same or different protein chains are attracted to each other.
t
14) Enzymes are biological catalysts.
t
15) One model to explain the inhibition of enzymes involves having the inhibitor bind to the enzyme at a site distant from the active site. The enzyme then changes shape so that the substrate no longer fits into the active site.
t
18) Pyrimidines have only one ring, while purines have two.
t
2) The series of chemical reactions that keep cells alive are known as metabolism.
t
20) There are 64 possible base triplets for 20 amino acids.
t
21) The genetic code for protein synthesis is known.
t
22) Introns are inactive portions in genes.
t
24) The RNA molecule that carries the information that determines the sequence of amino acids in a protein is mRNA.
t
25) DNA fingerprinting can be used to show that someone is innocent of a crime.
t
27) 86% of the corn planted in the U.S. is genetically modified.
t
7) Triglycerides with a high proportion of saturated fatty acids have a higher melting point than triglycerides with a low proportion of saturated fatty acids do.
t
8) Proteins are polymers consisting of amino acid monomers.
t