Replication begins at a point in the DNA called the ___.
a. promoter site
b. origin
c. template strand
d. transcription site
A group of genes under control of one promoter site is a(n) ___.
a. recombinant DNA
b. operon
c. reverse transcription
d. mutation
To form the molecule below, dehydration takes place at C1 of the pentose ring and at an N-H hydrogen at position ___ of the purine base.
a. 6
b. 1
c. 9
d. 7
Which of the following organic bases is found in DNA and not in RNA?
a. guanine
b. cytosine
c. thymine
d. uracil
The ___ has a "cloverleaf" shape and carries the amino acids to the site of protein synthesis.
a. transfer RNA
b. messenger RNA
c. ribosomal RNA
d. transfer DNA
Which of the following organic bases is a purine derivative?
a. Cytosine
b. Thymine
c. Pyrimidine
d. Guanine
___ is any permanent change in the primary structure of DNA.
a. Recombinant DNAb. Gene expressionc. Operon
d. Mutation
A cyclic nucleotide is produced when
a. the monosaccharide in the nucleotide is in the closed form.
b. the nitrogen base is in the cyclic form.
c. the phosphate attaches to the monosaccharide and the base.
d. the phosphate attaches to the monosaccharide in two places.
When a purine or pyrimidine base is combined with a sugar residue such as ribose or deoxyribose, the resulting compound is known as a ___.
a. nucleoside
b. nucleotide
c. polynucleotide
d. oligonucleotide
tRNA is a type of RNA that is responsible for
a. transferring the information for protein synthesis from DNA to the ribosomes.
b. supplying amino acids to the site of protein synthesis.
c. carrying the newly formed protein out of the nucleus of the cell.
d. cutting long proteins into shorter molecules when the proteins are needed by the cell.
If BRCA1 and BRCA2 genes are defective
a. the probability of breast cancer is increased for women, but not for men.
b. the genes can be repaired by recombinational repair.
c. the probability of having breast cancer is nearly 100%.
d. the risk of having breast cancer rises from below 15% to as much as 85%.
Which of the following organic bases is found in RNA and not in DNA?
a. guanine b. cytosine c. thymine
d. uracil
The process by which DNA unwinds and synthesizes a copy of new DNA is known as ___.
a. replication
b. transcription c. translation d. reverse transcription
In the double strand of DNA, the sugar-phosphate backbones with their negatively charged phosphate groups are on the inside and the bases are on the outside.Select one:
False
A characteristic of RNA that is not shared with DNA is
a. RNA is not found in the nucleus of cells; DNA is found in the nucleus.
b. the backbone of RNA does not contain phosphate.
c. RNA substitutes A for C in the base pairings.
d. RNA molecules are composed of a single strand.
Although the primary structures of proteins and DNA are defined in the same manner, the secondary structures are not. The secondary structure of DNA is
a. the β-helix formed by the strand
b. the sheets of DNA molecules laying side-by-side
c. the globular portions of the DNA structure
d. the double helix
A nucleoside triphosphate contains two phosphoanhydride bonds.
True
The following is a sugar found in nucleic acids:
It is
___ and is found in the nucleic acid ___.
a. ribose/DNA
b. 2-deoxyribose/DNA
c. ribose/RNAd.
2-deoxyribose/RNA
The bases adenine, guanine, and uracil are used in both DNA and RNA nucleotides.
FALSE
DNA polymerase is an enzyme involved in which process?
a. replication
b. transcription
c. translation
d. reverse transcription
IF DNA is heated and then cooled,
a. the DNA becomes denatured and then renatured.
b. the DNA becomes denatured and then twists into new shapes.c. the strands of DNA separate and then come together end to end.d. the strands of DNA establish more chemical bonds than before the heating.
The triphosphate in ATP is linked to C-5’ of the ribose by
a. a β-N-glycosidic linkage.
b. a phosphoester bond.
c. a peptide bond.d. a hydrogen bond.
Polynucleotides have definite 5’ and 3’ ends (terminus).
TRUE
Among the mechanisms Escherichia coli has for the control of β-galactosidase production is
a. that the combination of cAMP and CAP restricts the ability of RNA polymerase to function.b. the presence of the
b. the presence of the lac operon necessary for the production of the enzyme to be halted reducing overproduction.
c. that glucose must be absent and galactose present for the production to begin.d. that the speed with which the enzyme is produced is accelerated by the presence of both galactose and glucose.
Which of the following determines the primary structure of both DNA and RNA?
a. the sequence of sugar moleculesb. complimentary base pairingc. coiling of the helices into a tight, compact shaped. the sequence of nucleotide residues
d. the sequence of nucleotide residues
Which of the following sequence of bases in the DNA strand will be complimentary to the single DNA strand shown here to produce a double strand?
a. 5’ G-A-T-T-A-G-G-A-A 5’
b. 5’ C-G-A-A-T-C-C-T-A 3’
c. 3’ C-C-G-T-G-G-G-A-T 5’
d. 3’ G-C-T-T-A-G-G-A-T 5’
The following structure is known as a ___.
a. nucleoside
b. nucleotide
c. polynucleotided. oligonucleotide
Two strands of DNA are held in position relative to each other by means of ___.
a. covalent bondsb. ionic bondsc. disulfide bonds
d. hydrogen bonding
DNA and RNA
a. differ in both their monosaccharide and nitrogen base components
.b. contain the same nitrogen bases, but different monosaccharides.c. have the same composition, except for the monosaccharides.d. are both produced by animals, but RNA is not produced by plants.
Transgenic goats have had human genes inserted into their DNA that code for the production of which of following serum protein anticoagulants?Select one:
a. thrombin
b. hemoglobin
c. antithrombin
d. insulin
What is present in a nucleotide that is not found in a nucleoside?
a. a phosphate
b. a monosaccharidec. an alcohol groupd. a nitrogen base
Glycolysis is controlled in steps:
a. 1, 2, and 3b. 2, 5 and 7
c. 1, 3 and 10
d. 3, 5 and 8
How do the monosaccharides produced during digestion get into the circulatory system?
a. They are absorbed by the cells in the intestinal lining and are released into the blood.
b. They are absorbed by the cells in the stomach lining and released into the blood.c. They are able to move between the cells of the stomach lining directly into the blood.d. They are transported by the action of the cell membranes of the digestive tract.
___ is defined as the reactions that break down large molecules into small ones and release energy in the form of ATP.
a. Metabolism
b. Catabolism
c. Anabolismd. Hydrolysis
Which of the choices below present products of the citric acid cycle?
a. ATP, ADP, and CO2
b. NADH, FADH2, and GTP
c. FAD, NAD+, ADP, and H2O
d. CO2, H2O, ATP, and GTP, and NAD+
The amount of energy obtained from hydrolysis of ATP is
a. -11.8 kcal.b. - 36 kcal.c. -4.5 kcal.
d. -7.3 kcal.
Gluconeogenesis is a process by which glucose is produced
a. in the liver from noncarbohydrate sources.
b. in the mitochondrion if there is an excess of fructose.c. by the enzymes located on the cristae.d. by exactly reversing the process of glycolysis.
In a coupled reaction of a metabolic pathway, a spontaneous reaction provides the energy needed by a nonspontaneous one.
True
A metabolic pathway in which the product of one reaction is the reactant in the next reaction in a continuous series is defined as a ___ pathway
a. linear
b. circularc. spirald. coupled
The digestion of proteins begins in the stomach with hydrolysis being catalyzed by ___.
a. chymotrypsin
b. pepsin
c. amylase
d. lipase
Amylase
a. is an enzyme that continues functioning in the stomach.b. is the only enzyme in the saliva that hydrolyzes proteins.c. is a carbohydrate easily digested in the stomach.
d. catalyzes hydrolysis of some of the bonds in amylose.
Which choice is a goal of catabolism?
a. the production of heatb. the attachment of the coenzyme A residue
c. the generation of ATP molecules
d. the production of two-carbon fragments
One step in the catabolism of glucose involves the conversion of glucose 6-phosphate into ___.
a. glucose
b. fructose 6-phosphate
c. glucose 3-phosphated. pyruvate
Which of the following products are formed in one pass through the -oxidation spiral when a fatty acyl-CoA is shortened by two carbon atoms?
a. NADH and pyruvate
b. FADH2 and pyruvate
c. NADH and FADH2
d. ATP and glycogen
The citric acid cycle has which step as a main control?
a. step 3, isocitrate α-ketoglutarate
b. step 1, acetyl-CoA citratec. step 7, fumarate malated. step 8, malate oxaloacetate
The acetyl-CoA from the fatty acid catabolism enters the ___ whereas the reduced coenzymes NADH and FADH2 enter ___.Select one:
a. citric acid cycle/the electron transport chain
b. electron transport chain/glycolysis
c. citric acid cycle/glycolysis
d. glycolysis/the citric acid cycle
The compounds needed to start the citric acid cycle are
a. acetyl-CoA and citrate.b. isocitrate and NAD+.c. acetyl-CoA and NADH.
d. acetyl-CoA and oxaloacetate.
If acetyl-CoA concentrations reach too high levels,
a. ketone bodies can be produced leading to a toxic condition.
b. the citric acid cycle increases in reaction rate to use the excess acetyl-CoA.c. pathways other than the citric acid cycle activate to remove the excess acetyl-CoA.d. the ketone bodies are stored in special cells and used as a source of energy when required.
Lipogenesis
a. produces fatty acids by means of a spiral pathway.b. produces fatty acids by joining two carbon atoms at a time.c. does not produce all of the fatty acids required by humans.
d. All of these answer choices are correct.
___ takes place in the cytoplasm while ___ takes place in the mitochondria.
a. Citric acid cycle/electron transport chainb. Electron transport chain/glycolysisc. Citric acid cycle/glycolysis
d. Glycolysis/citric acid cycle
Most of triglyceride digestion occurs in the ___.
a. mouthb. stomach
c. small intestine
d. liver
Sometimes the reduction of oxygen to water is incomplete, resulting in
a. a greater production of ATP because there are more hydrogen ions present.
b. toxic products, which are superoxide or hydrogen peroxide.
c. a greater production of FADH2 from the extra hydrogen ions.d. hydrogen gas, which can be excreted and does not build up.
In a cell, fatty acid biosynthesis occurs in ___.
a. mitochondria
b. the cytoplasm
c. the nucleus
d. lysosome
Catabolism reactions are those that produce more complex molecules from the simpler molecules along with a release of energy.
FALSE
During glycolysis and under aerobic conditions, pyruvate is converted into ___.
a. lactate
b. acetyl-CoA
c. ketonesd. ADP
A metabolic pathway in which a series of reactions is used to repeatedly break down or build up a molecule is defined as a ___ pathway.
a. linearb. circular
c. spiral
d. coupled
Glycogen can be broken down to form glucose 1-phosphate, which is directly involved in glycolysis.
TRUE
Where in a cell do the formation of acetyl-CoA and the citric acid cycle occur?
a. cytoplasm
b. mitochondria
c. nucleusd. lysosome
The following structure represents which of the following nucleotides?
a. UMP
b. GDP
c. GTP
d. ATP
The function of RNA polymerase is to
a. cause the RNA molecule to increase in length during protein production.
b. cause the RNA molecule to coil into a shape that helps in DNA replication.
c. disrupt the double helix by isolating one strand from the other.
d. synthesize an RNA molecule that remains attached to the DNA.
Which is involved in expression?
a. replicationb. transcriptionc. translation
d. both transcription and translation
Chromatin is a molecule that
a. is produced from chromosomes during early cell reproduction.
b. coils and folds to become a chromosome before cell division occurs.
c. is a special form of DNA where protein interacts with the nitrogen bases.
d. is a special part of the tertiary structure of DNA composed of a single helix.
The structures of DNA and RNA
alternate monosaccharide and phosphate components.b. have a nitrogen base projecting off each monosaccharide.c. are due to the chemical bond between the nitrogen base and the
c. are due to the chemical bond between the nitrogen base and the phosphate
d. have alternate monosaccharide and phosphate components and have a nitrogen base projecting off each monosaccharide.
___ is exclusively used to for reductive biosynthesis reactions.
a. NADPH
b. ATP
c. ADP
d. NAD+
During oxidative deamination
a. ammonium ions are removed from one amino acid and placed on another amino acid.b. oxygen reacts with the amino acid releasing nitrogen-oxygen compounds.c. new compounds are produced by the addition of a carboxyl group.
d. potentially toxic ammonium ions are produced.
___ is the sum of all of the reactions that take place in a living thing.
a. Metabolism
b. Catabolismc. Anabolismd. Hydrolysis
The location in the cell where ATP is produced is the ___.
a. mitochondria
b. lysosomec. nucleusd. cell membrane
The allosteric enzyme phospofructokinase is switched off by ___.
a. glucose
b. isocitratec. AMP
d. ATP
The following image is a sugar found in nucleic acids:
It is ___ and is found in the nucleic acid ___.
a. ribose/DNAb. deoxyribose/DNA
c. ribose/RNA
d. deoxyribose/RNA
Thymine is a base found in RNA and not in DNA.
false
ow many bonds are broken when the following molecule is completely hydrolyzed?
a. 2
b. 1c. 3d. 4
The fatty acids produced from the hydrolysis of triglycerides can
a. be used to enter directly into glycolysis, producing extra ATP.
b. be oxidized to produce acetyl-CoA, which enters the citric acid cycle.
c. produce glucose by a pathway separate from gluconeogenesis.
d. be modified to undergo either glycolysis or gluconeogenesis.
The total NADH produced in one citric acid cycle are ___.
a. 3
b. 2c. 4d. 6