euk

Question NumberQ 2: A shortage of cholesterol in the body could interfere with the formation of: A Option A: cell membranes. B Option B: testosterone. C Option C: all of the choices are correct. D Option D: progesterone. E Option E: estrogen.

C Option C: all of the choices are correct.

Q 5: Which of the following statements is FALSE, according to the First Law of Thermodynamics? A Option A: Energy can neither be created nor destroyed. B Option B: The First law of thermodynamics is demonstrated during photosynthesis. C Option C: Energy cannot be transformed from one form to another. D Option D: Energy is defined as the capacity to do work.

C Option C: Energy cannot be transformed from one form to another.

Q 3: Which of the following statements is false, according to the Second Law of Thermodynamics? A Option A: Spontaneous events occur without the input of external energy. B Option B: Events in the universe tend to move from a state of higher energy to a state of lower energy. C Option C: In any energy transformation, there is an increasing availability of energy for doing additional work. D Option D: Events in the universe have direction. E Option E: The change in available energy during a process is a result of a tendency for the randomness, or disorder, of the universe to increase every time there is a transfer of energy.

C Option C: In any energy transformation, there is an increasing availability of energy for doing additional work.

Question NumberQ 3: Bacterial resistance to antibiotics may occur by each of the following mechanisms EXCEPT: A Option A: increased pumping of the antibiotic out of the cell once it has entered. B Option B: development of an enzyme that can break down the structure of the antibiotic. C Option C: a high rate of mutation. D Option D: mutations in the target of the antibiotic. E Option E: modifications in the cell wall that prevent entry of the antibiotic.

C Option C: a high rate of mutation.

Question NumberQ 2: Exergonic reactions: A Option A: require input of energy to occur. B Option B: are thermodynamically unfavorable. C Option C: can occur spontaneously. D Option D: can be made to occur by coupling them to energy-releasing processes. E Option E: have a positive ΔG.

C Option C: can occur spontaneously.

Question NumberQ 1: How many polypeptide chains comprise a hemoglobin molecule? A Option A: two or four B Option B: two C Option C: four D Option D: one E Option E: three

C Option C: four

Question NumberQ 2: The liver stores energy in the form of a polysaccharide called: A Option A: starch. B Option B: fiber. C Option C: glycogen. D Option D: glucose. E Option E: cellulose.

C Option C: glycogen.

Question NumberQ 2: When a sugar cube is dissolved in a cup of coffee, the entropy of the sugar: A Option A: is unchanged. B Option B: decreases. C Option C: increases.

C Option C: increases.

Question NumberQ 1: NADPH represents reducing power in the cell because: A Option A: it is oxidized during the process of glycolysis. B Option B: it is a source of phosphate groups to produce ATP. C Option C: it has high electron-transfer potential. D Option D: it is the same as NADH. E Option E: it is reduced during the process of glycolysis.

C Option C: it has high electron-transfer potential.

Question NumberQ 1: Which of the following was the first protein whose tertiary structure was determined? A Option A: hemoglobin B Option B: insulin C Option C: myoglobin D Option D: actin E Option E: collagen

C Option C: myoglobin

Q 1: When an enzyme is functioning at Vmax, the rate of the reaction is limited by: A Option A: the concentration of the substrate. B Option B: the number of substrate molecules in the reaction. C Option C: the concentration of the enzyme. D Option D: the number of collisions between enzyme and substrate. E Option E: the value of Km.

C Option C: the concentration of the enzyme.

Question NumberQ 3: The variability among polypeptides is primarily due to: A Option A: noncovalent interactions within the molecule. B Option B: the addition of sulfate groups to some amino acids. C Option C: the diverse side chains on the different amino acids. D Option D: addition of a phosphate group. E Option E: the length of the polypeptide chain.

C Option C: the diverse side chains on the different amino acids.

Question NumberQ 3: As opposed to in an uncatalyzed reaction, in an enzymatically catalyzed reaction: A Option A: the activation energy of the reaction is increased, thus decreasing the likelihood that any substrate molecules will overcome it. B Option B: the activation energy of the reaction is lowered, but fewer substrate molecules can overcome it. C Option C: the activation energy of the reaction is increased, but the substrate molecules are highly energized. D Option D: the activation energy of the reaction is lowered, and a larger proportion of substrate molecules has sufficient energy to overcome it. E Option E: the activation energy of the reaction remains unchanged, but the substrate molecules are highly energized.

D Option D: the activation energy of the reaction is lowered, and a larger proportion of substrate molecules has sufficient energy to overcome it.

Question NumberQ 1: For a reaction with a standard free energy change, ΔG'° = +0.7 kcal/mole, which of the following statements is TRUE? A Option A: The reaction is exergonic. B Option B: None of the choices is correct. C Option C: The reaction would always occur spontaneously. D Option D: The reaction could be made to occur by altering the concentrations of reactants and products. E Option E: The reaction would not occur in a living cell.

D Option D: The reaction could be made to occur by altering the concentrations of reactants and products.

Q 3: Which of the following statements CANNOT be used to describe a viral infection? A Option A: The virus may insert its genetic material into the DNA of the host. B Option B: The virus may direct production and assembly of new viruses within the host cell and cause it to lyse. C Option C: The virus inserts its genetic material into the host cell DNA, but may be stimulated to separate from the host's DNA and begin production of new viruses that lyse the cell. D Option D: The virus divides within the host cell forming two new viruses that also divide within the host cell; those two viruses divide to form four viruses within the host cell. E Option E: The virus may disrupt the DNA of the host cell leading to growth of a tumor.

D Option D: The virus divides within the host cell forming two new viruses that also divide within the host cell; those two viruses divide to form four viruses within the host cell.

Question NumberQ 4: Entropy is: A Option A: an increase in available energy. B Option B: the ability to perform work. C Option C: not applicable to living systems. D Option D: a tendency for randomness to increase every time there is a transfer of energy. E Option E: an increase of order in the universe.

D Option D: a tendency for randomness to increase every time there is a transfer of energy.

Question NumberQ 2: Study of the proteome of a cell: A Option A: requires use of a computer to compare fingerprints of extracted proteins to those of known proteins. B Option B: can reveal changes in protein composition within a cell over time. C Option C: is furthered by mass spectrometry that provides a pattern characteristic of individual proteins. D Option D: all of these statements are true. E Option E: is based on knowledge of the genome of a cell.

D Option D: all of these statements are true.

Question NumberQ 2: Because they both associate with proteins that assist in the assembly of their subunits, Rubisco is MOST similar to: A Option A: BiP. B Option B: GroES. C Option C: green fluorescent protein (GFP). D Option D: antibody molecules. E Option E: heat shock proteins.

D Option D: antibody molecules.

Q 3: The study of proteins using siRNA's is MOST useful in determining: A Option A: protein denaturation. B Option B: changes in protein composition within the cell over time. C Option C: the DNA sequence that codes for a protein. D Option D: the function of a protein. E Option E: protein structure.

D Option D: the function of a protein.

Q 1: Self-assembly of complex molecular structures was first demonstrated in studies of: A Option A: cytoskeleton. B Option B: molecular chaperones. C Option C: hemoglobin. D Option D: tobacco mosaic virus. E Option E: ribosomes.

D Option D: tobacco mosaic virus.

Question NumberQ 1: Modifications allowing the use of X-ray crystallography to study enzyme catalysis include all of the following EXCEPT: A Option A: cooling the reaction temperature to temperatures close to absolute zero. B Option B: using X-ray beams of increased intensity. C Option C: using enzymes modified by site-directed mutagenesis. D Option D: use of higher energy gamma rays. E Option E: determination of structure using ultra-high resolution.

D Option D: use of higher energy gamma rays.

Q 2: Which one of the following structures is the smallest? A Option A: nucleus B Option B: eukaryotic cell C Option C: neuron D Option D: protein E Option E: prokaryotic cell

D protein

Noncompetitive inhibitors: A Option A: are similar in structure to the substrate, but are not converted to product due to interaction with the enzyme. B Option B: lose their effectiveness when substrate level increases. C Option C: bind to the active site of the enzyme. D Option D: bind to a site on the enzyme other than the active site for the substrate. E Option E: bind irreversibly to the enzyme.

D Option D: bind to a site on the enzyme other than the active site for the substrate.

Q 2: Tertiary structure of a protein is stabilized by: A Option A: addition of methyl groups. B Option B: hydrogen bonds between amino acids. C Option C: peptide bonds between amino and carboxyl groups on adjacent amino acids. D Option D: bonds between side chains of amino acids. E Option E: an aqueous environment.

D Option D: bonds between side chains of amino acids.

Question NumberQ 3: Denaturation of a protein: A Option A: does not result in loss of function of the protein. B Option B: occurs at very low temperatures. C Option C: is the mechanism by which stabilization of the protein structure is achieved. D Option D: can be caused by detergents, organic solvents, or radiation. E Option E: interfere with covalent bonding that stabilizes the protein's tertiary structure.

D Option D: can be caused by detergents, organic solvents, or radiation.

Question NumberQ 1: Bacterial enzymes upon which antibiotics may act do NOT include those involved in: A Option A: folding of β-lactam. B Option B: endospore formation. C Option C: breakdown of cell membrane components. D Option D: glycolysis. E Option E: DNA replication.

D Option D: glycolysis.

Question NumberQ 1: Molecular chaperones were originally referred to as: A Option A: Rubisco. B Option B: chaperonins. C Option C: Hsp60. D Option D: heat shock proteins. E Option E: GroEL.

D Option D: heat shock proteins.

Question NumberQ 1: Different versions of a protein, which are known as ________, are adapted to function in different tissues or at different stages of development. A Option A: families B Option B: homologous C Option C: subunits D Option D: isoforms E Option E: mutations

D Option D: isoforms

Question NumberQ 2: Ribosomal RNA: A Option A: carries the genetic message that is translated at the ribosome. B Option B: may act as a ribozyme during protein synthesis. C Option C: retrieves amino acids and brings them to the ribosome for incorporation into a growing protein. D Option D: may have double stranded regions due to hairpin loop formations. E Option E: is a double-stranded helix.

D Option D: may have double stranded regions due to hairpin loop formations.

Question NumberQ 1: Protein catalysts: A Option A: are sometimes referred to as ribozymes. B Option B: decrease the rates of chemical reactions in cells while remaining unchanged. C Option C: cannot change the standard free energy of a cellular reaction. D Option D: permit the energy of activation to be lowered in a reaction. E Option E: cannot enable a reaction that is otherwise energetically unfavorable.

D Option D: permit the energy of activation to be lowered in a reaction.

Question NumberQ 2: The hydrolysis of ATP can be used in the cell to drive reactions leading to the formation of molecules such as glutamine because: A Option A: ATP and ADP concentrations are equal. B Option B: ATP concentrations in most cells are 10 to 100 times less than the concentration of ADP. C Option C: ADP concentration is more than 107 times that of ATP. D Option D: ATP levels are maintained at much lower levels (relative to those of ADP) than they would be at equilibrium. E Option E: ATP levels are maintained at much higher levels (relative to those of ADP) than they would be at equilibrium.

E Option E: ATP levels are maintained at much higher levels (relative to those of ADP) than they would be at equilibrium.

Question NumberQ 1: Spongiform encephalopathy describes all of the following diseases EXCEPT: A Option A: Mad cow disease. B Option B: Kuru. C Option C: Creutzfeld-Jakob disease. D Option D: Elk wasting disease. E Option E: Alzheimer's disease.

E Option E: Alzheimer's disease.

Question NumberQ 1: What is the MOST important function of fermentation from the point of view of the cell? A Option A: Fermentation is the basis of the wine, beer, and liquor industries. B Option B: Fermentation provides a supply of lactate to metabolizing muscle cells. C Option C: Fermentation is an essential step in aerobic metabolism. D Option D: Fermentation produces a small amount of ATP. E Option E: Fermentation regenerates NAD+ so that glycolysis can continue.

E Option E: Fermentation regenerates NAD+ so that glycolysis can continue.

Question NumberQ 2: The scientist who elucidated the three-dimensional structure of hemoglobin is: A Option A: John Kendrew. B Option B: Robert Corey. C Option C: Linus Pauling. D Option D: Frederick Sanger. E Option E: Max Perutz.

E Option E: Max Perutz.

Q 1: Which of the following statements is TRUE according to the endosymbiotic theory? A Option A: None of the choices are correct. B Option B: Bacterial flagella have the same evolutionary origin as eukaryotic flagella. C Option C: Photosynthetic algae evolved from plants. D Option D: Bacteria were engulfed by larger cells and became the nucleus of those cells. E Option E: Mitochondria and chloroplasts developed from organisms that were once free-living.

E Option E: Mitochondria and chloroplasts developed from organisms that were once free-living.

Q 2: Which one of the following statements is FALSE? A Option A: Small changes in amino acid sequence may have dramatic effects on protein shape. B Option B: Proteins are biochemical adaptations that are subject to evolutionary change. C Option C: The greater the evolutionary distance between two organisms, the greater the difference in the amino acid sequences of their proteins. D Option D: Genes that encode members of a protein family are thought to have arisen from a single ancestral gene. E Option E: Proteins with identical sequences of amino acids must also have identical folding patterns.

E Option E: Proteins with identical sequences of amino acids must also have identical folding patterns.

Question NumberQ 1: Which of the following characteristics does NOT apply to water? A Option A: The covalent bonds in water are strongly polarized. B Option B: The water molecule is asymmetric. C Option C: All three atoms in the water molecule ready form hydrogen bonds. D Option D: Water is an excellent solvent. E Option E: The water molecule readily forms hydrophobic interactions.

E Option E: The water molecule readily forms hydrophobic interactions.

Question NumberQ 2: Prions: A Option A: are a treatment for CJD developed by Stanley Prusiner. B Option B: cause Alzheimer's disease. C Option C: are a type of virus. D Option D: destroy the cells lining the gastrointestinal tract. E Option E: are a type of infectious agent composed only of protein.

E Option E: are a type of infectious agent composed only of protein.

Question NumberQ 2: The first protein to have its amino acid sequence determined was: A Option A: spider silk. B Option B: myoglobin. C Option C: hemoglobin. D Option D: keratin. E Option E: beef insulin.

E Option E: beef insulin.

Question NumberQ 3: Silk is composed of a protein containing a large amount of: A Option A: alpha (α) helix conformations. B Option B: disulfide bridges. C Option C: proline. D Option D: quaternary structure. E Option E: beta (β) sheet conformations.

E Option E: beta (β) sheet conformations.

Question NumberQ 1: Reactions that have positive standard free energy changes (ΔG'°>0) can be made to occur in cells by: A Option A: coupling them with exergonic reactions via a common intermediate. B Option B: both coupling them with exergonic reactions via a common intermediate and coupling them to the synthesis of ATP. C Option C: coupling them to the synthesis of ATP. D Option D: manipulating the concentrations of products and reactants such that ΔG'<0. E Option E: both coupling them with exergonic reactions via a common intermediate and manipulating the concentrations of products and reactants such that ΔG'<0.

E Option E: both coupling them with exergonic reactions via a common intermediate and manipulating the concentrations of products and reactants such that ΔG'<0.

Question NumberQ 2: Disulfide bridges can form between two residues of: A Option A: proline. B Option B: arginine. C Option C: glycine. D Option D: histidine. E Option E: cysteine.

E Option E: cysteine.

Question NumberQ 3: Antioxidants are believed to: A Option A: cause cancer. B Option B: generate free radicals. C Option C: break down hydrogen peroxide. D Option D: break down vitamins. E Option E: destroy free radicals.

E Option E: destroy free radicals.

Q 3: Hemoglobin A1c can be measured in blood tests to track the progress of which disease? A Option A: anorexia B Option B: kidney disease C Option C: liver disease D Option D: heart disease E Option E: diabetes

E Option E: diabetes

1: Atoms or molecules that have an orbital with a single unpaired electron are called: A Option A: acids. B Option B: antioxidants. C Option C: ions. D Option D: stable. E Option E: free radicals.

E Option E: free radicals.

Question NumberQ 2: Weak attractions between adjacent water molecules are: A Option A: ionic bonds. B Option B: polar covalent bonds. C Option C: van der Waals forces. D Option D: hydrophobic interactions. E Option E: hydrogen bonds.

E Option E: hydrogen bonds.

Question NumberQ 4: A provirus: A Option A: caused the influenza epidemic of 1918. B Option B: was the first virus discovered by Wendell Stanley at the Rockefeller Institute. C Option C: is composed of DNA or RNA surrounded by a protein capsid. D Option D: infects bacterial cells. E Option E: is viral DNA integrated into host DNA.

E Option E: is viral DNA integrated into host DNA.

Question NumberQ 2: Molecular chaperones: A Option A: all of these choices are true of molecular chaperones. B Option B: direct proteins out of the nucleus and into the cytoplasm. C Option C: direct proteins out of the cell through the plasma membrane. D Option D: are carbohydrates that attach to specific amino acids. E Option E: may prevent growing proteins from random interaction with other proteins in the cytoplasm.

E Option E: may prevent growing proteins from random interaction with other proteins in the cytoplasm.

Question NumberQ 1: Cellular metabolism is an example of: A Option A: a series of reactions occurring under standard conditions. B Option B: a series of reactions that defy the second law of thermodynamics. C Option C: equilibrium metabolism. D Option D: a closed system. E Option E: steady-state metabolism.

E Option E: steady-state metabolism.

Question NumberQ 1: The MOST important transduction of energy in the biological world is: A Option A: the ability of fireflies to convert chemical energy into light. B Option B: the burning of gasoline to power vehicles. C Option C: the generation of thermal energy when we shiver in the cold. D Option D: the conversion from mechanical energy to electrical energy in wind turbines. E Option E: the conversion of sunlight into chemical energy in the process of photosynthesis.

E Option E: the conversion of sunlight into chemical energy in the process of photosynthesis.

Which of the following does NOT account for the small size of cells? A Option A: the distance from the cell interior to the cell surface B Option B: the surface area/volume ratio C Option C: the number of mRNAs that can be produced by the nucleus D Option D: the rate of diffusion E Option E: the length/surface area ratio

E Option E: the length/surface area ratio

Q 5: Bacteriophages are attractive tools to use in combating bacterial infections because of all the following reasons EXCEPT: A Option A: they have a broad host range. B Option B: they can provide immunity by inserting their DNA into human cells. C Option C: they mutate readily should pathogens also alter their genetic virulence. D Option D: many bacteria are resistant to our antibiotics. E Option E: they are more expensive than drugs.

E Option E: they are more expensive than drugs.

In a polypeptide, when peptide bonds are formed between adjacent amino acids: A Option A: the carboxyl group of one amino acid joins with the amino group of the adjacent amino acid and water is lost. B Option B: the carboxyl groups of two adjacent amino acids are joined by a covalent bond. C Option C: the protein folds into a complex shape. D Option D: a water molecule is gained by the carboxyl group. E Option E: the amino groups of two adjacent amino acids are attracted by hydrogen bonds.

A Option A: the carboxyl group of one amino acid joins with the amino group of the adjacent amino acid and water is lost.

Question NumberQ 2: The turnover number for an enzyme tells you: A Option A: the maximum number of molecules of substrate that can be converted to product by one enzyme molecule per unit time. B Option B: the substrate concentration at one-half of Vmax. C Option C: the enzyme concentration at Vmax. D Option D: the minimum number of enzyme molecules that can convert a substrate molecule to product per unit of time. E Option E: the amount of substrate that can saturate the enzyme.

A Option A: the maximum number of molecules of substrate that can be converted to product by one enzyme molecule per unit time.

Question NumberQ 2: Sulfa drugs are effective against bacterial cells because: A Option A: they resemble the substrate that their cells enzymatically convert to folic acid. B Option B: they bind to bacterial ribosomes and prevent protein synthesis. C Option C: they interfere with reactions that produce the rigid bacterial cell wall. D Option D: they inhibit the enzyme DNA gyrase that is required for bacterial DNA replication. E Option E: they are genetically engineered to prevent antibiotic resistance.

A Option A: they resemble the substrate that their cells enzymatically convert to folic acid.

Q 1: The process of predicting the tertiary structure of the unknown protein by aligning the amino acids of the unknown protein onto the corresponding amino acids in the protein whose structure is known is called: A Option A: threading. B Option B: x-ray crystallography. C Option C: denaturation. D Option D: self-assembly. E Option E: chaperoning.

A Option A: threading.

Question NumberQ 3: Substrate-level phosphorylation does NOT involve: A Option A: transfer of electrons to oxygen. B Option B: transfer of a phosphate group to ADP. C Option C: involves transfer of a phosphate group from a donor with higher transfer potential to an acceptor with less transfer potential. D Option D: derivatives of glucose. E Option E: involves transfer of a phosphate group from a donor with greater free energy to an acceptor with less free energy.

A Option A: transfer of electrons to oxygen

What is the main advantage of small cell size? A Option A: Small cells have more surface area-to-volume ratio across which to take up nutrients and get rid of waste products. B Option B: It takes less energy to construct an organism using small cells. C Option C: Small cells don't require as many genes. D Option D: Large cells are more vulnerable to infection. E Option E: Small cells are less likely to burst in dilute environments.

A Small cells have more surface area-to-volume ratio across which to take up nutrients and get rid of waste products.

Question NumberQ 3: The three domains of living organisms described by Carl Woese are: A Option A: archaea, bacteria, eukaryotes. B Option B: prokaryotes, eukaryotes, archaea. C Option C: plants, animals, bacteria. D Option D: aquatic, terrestrial, airborne. E Option E: bacteria, viruses, eukaryotes.

A archaea, bacteria, eukaryotes.

Question NumberQ 2: The major cellular macromolecules include: A Option A: proteins, nucleic acids, polysaccharides, and antibodies. B Option B: proteins, nucleic acids, polysaccharides, and lipids. C Option C: proteins, lipids, amino acids, and polysaccharides. D Option D: proteins, amino acids, lipids, and nucleic acids. E Option E: proteins, steroids, polysaccharides, and nucleic acids.

B Option B: proteins, nucleic acids, polysaccharides, and lipids.

Question NumberQ 2: Carl Woese's evolutionary studies that led him to propose the three domain taxonomic system compared nucleotide sequences present in: A Option A: cyanobacteria. B Option B: 16S rRNA genes. C Option C: DNA polymerase genes. D Option D: thermophiles. E Option E: the nuclei of eukaryotic cells.

B Option B: 16S rRNA genes.

Question NumberQ 3: _______________ are particular groupings of atoms that often behave as a unit and give organic molecules their physical properties, chemical reactivity, and solubility in aqueous solution. A Option A: Hydrocarbons B Option B: Functional groups C Option C: Metabolic intermediates D Option D: Proteins E Option E: Polymers

B Option B: Functional groups

Question NumberQ 1: Which statement(s) are FALSE regarding site-directed mutagenesis? A Option A: It requires codon alteration. B Option B: It does not result in a change in the structure of a protein. C Option C: It can be used to produce clinically useful proteins. D Option D: It can be used to predict the function of a protein. E Option E: It alters a DNA sequence to produce a specific change in a translated protein.

B Option B: It does not result in a change in the structure of a protein.

1: The genetic material within a virus is in the form of: A Option A: single-stranded RNA. B Option B: The genetic material within a virus may be any of these. C Option C: double-stranded DNA. D Option D: double-stranded RNA. E Option E: single-stranded DNA.

B Option B: The genetic material within a virus may be any of these.

Question NumberQ 5: Which of the following statements is NOT true of glycolysis? A Option A: The pathway requires two molecules of ATP to start the catabolism of each molecule of glucose. B Option B: The pathway oxidizes two molecules of NADH to NAD+ for each molecule of glucose that enters. C Option C: The pathway is anaerobic. D Option D: The pathway takes place in the cytoplasm of the cell. E Option E: ADP is phosphorylated to ATP via substrate-level phosphorylation.

B Option B: The pathway oxidizes two molecules of NADH to NAD+ for each molecule of glucose that enters.

Question NumberQ 4: Which of the following statements is NOT true about competitive enzyme inhibitors? A Option A: They bind to the active site of the enzyme. B Option B: They bind irreversibly to the enzyme. C Option C: They are less effective when substrate concentrations are high. D Option D: They bind reversibly to the enzyme. E Option E: They are similar in structure to the substrate, but are not converted to product due to interaction with the enzyme.

B Option B: They bind irreversibly to the enzyme.

Q 4: Conformational changes within a protein molecule are NOT seen in the following function: A Option A: opening or closing of a membrane channel. B Option B: binding of calcium to myosin. C Option C: muscle contraction. D Option D: binding of a substrate to an enzyme. E Option E: interaction between GroEL and GroES.

B Option B: binding of calcium to myosin.

Question NumberQ 3: Saturated fatty acids lack which of the following? A Option A: a glycerol molecule B Option B: double bonds between carbon atoms C Option C: single bonds between carbon atoms D Option D: a hydrocarbon chain E Option E: energy

B Option B: double bonds between carbon atoms

Question NumberQ 2: Which one of the following does NOT allow an enzyme to speed up a reaction? A Option A: formation of an enzyme-substrate complex B Option B: heating the reaction to temperatures higher than 50oC C Option C: facilitating correct orientation of a substrate D Option D: changing substrate reactivity E Option E: causing strain on the bonds within the substrate

B Option B: heating the reaction to temperatures higher than 50oC

Question NumberQ 3: Polar molecules are __________; nonpolar molecules are __________. A Option A: hydrophilic; hydrophilic B Option B: hydrophilic; hydrophobic C Option C: hydrophobic; hydrophobic D Option D: hydrophobic; hydrophilic E Option E: hydrophilic; either hydrophilic or hydrophobic

B Option B: hydrophilic; hydrophobic

Question NumberQ 3: The function of a buffer is to: A Option A: generate slight changes in pH. B Option B: maintain stable pH. C Option C: create a neutral pH.

B Option B: maintain stable pH.

Question NumberQ 1: The specific linear sequence of amino acids that form a polypeptide chain is its: A Option A: tertiary structure. B Option B: primary structure. C Option C: DNA sequence. D Option D: secondary structure. E Option E: quaternary structure.

B Option B: primary structure.

Question NumberQ 3: Strategies to develop medications to battle Alzheimer's disease have included: A Option A: antibiotics that prevent replication of prions. B Option B: removal of the Aβ β 42 peptide or the amyloid deposits that it produces. C Option C: fostering interaction between Aβ molecules to generate fibrillar aggregates. D Option D: procedures that encourage the formation of the Aβ β 42 peptide. E Option E: infecting transgenic mice with prions.

B Option B: removal of the A β β 42 peptide or the amyloid deposits that it produces.

Question NumberQ 3: At very low concentrations of substrate, the rate of a reaction is proportional to: A Option A: the concentration of enzyme. B Option B: the concentration of substrate molecules. C Option C: the combined effects of enzyme and substrate concentration. D Option D: the value of Vmax. E Option E: the combined effects of Vmax and enzyme concentration.

B Option B: the concentration of substrate molecules.

Question NumberQ 1: Which of the following is a pyrimidine found only in RNA? A Option A: cytosine B Option B: uracil C Option C: thymine D Option D: adenine E Option E: glycine

B Option B: uracil

Question NumberQ 3: To predict the direction in which a particular reaction will proceed at a given moment within a particular cellular compartment, one must know all of the following EXCEPT: A Option A: the temperature at which the cell is found. B Option B: whether the cell is marine or terrestrial. C Option C: standard conditions. D Option D: the concentrations of reactants and products. E Option E: the ratio of [ADP] / [ATP].

B Option B: whether the cell is marine or terrestrial.

Q 2: An enzyme that breaks down the superoxide radical (O2-) is: A Option A: superoxide dismutase. B Option B: catalase. C Option C: hydrogen peroxide. D Option D: glutathione. E Option E: vitamin C.

A Option A: superoxide dismutase.

: Viruses may be grown: A Option A: only in living cells. B Option B: in an incubator. C Option C: in pure cultures in the lab. D Option D: on chemical growth media. E Option E: in darkness or in light.

A Option A: only in living cells.

Question NumberQ 1: Cytoplasm has a pH of about 7. What is the concentration, in moles/liter, of the hydrogen ion? A Option A: 1 x 10-7 B Option B: 7 x 10-7 C Option C: 1 x 107 D Option D: 7 x 10-1 E Option E: 7

A Option A: 1 x 10-7

Question NumberQ 1: The human genome contains: A Option A: 20,000 to 22,000 genes. B Option B: 100,000 to 120,000 genes. C Option C: 1,000 to 2,000 genes. D Option D: 10,000 to 12,000 genes. E Option E: it's impossible to determine.

A Option A: 20,000 to 22,000 genes.

Question NumberQ 1: Which of the following are needed to form a triacylglycerol molecule? A Option A: 3 fatty acid molecules B Option B: 3 glycerol molecules C Option C: 3 trans fats D Option D: 3 phosphate groups E Option E: 3 carbon rings

A Option A: 3 fatty acid molecules

Q 2: As a solution becomes more acidic: A Option A: H+ concentration increases and pH decreases. B Option B: H+ concentration increases. C Option C: pH decreases. D Option D: pH increases. E Option E: H+ concentration decreases.

A Option A: H+ concentration increases and pH decreases.

Question NumberQ 1: Of the following elements, which is likely to form the least polar covalent bonds with hydrogen? A Option A: Hydrogen B Option B: Carbon C Option C: Nitrogen D Option D: Phosphorus E Option E: Oxygen

A Option A: Hydrogen

Question NumberQ 2: Which of these exemplifies the cell as an open system? A Option A: Metabolism requires constant input of oxygen. B Option B: Metabolic reactions are not dependent upon enzyme activity. C Option C: The concentrations of reactants and products of metabolism are highly variable. D Option D: The products of metabolism are recycled within the organism. E Option E: The direction of metabolism is constant and does not vary in response to changing conditions.

A Option A: Metabolism requires constant input of oxygen.

Question NumberQ 2: Which one of the following statements is TRUE? A Option A: NADPH is used by enzymes in the cell that have a reductive role in anabolic pathways. B Option B: NADPH production is favored over production of NADH when energy in the cell is scarce. C Option C: The oxidized form of NADPH is NAD+. D Option D: NADP+ can act as an oxidizing agent for NADH. E Option E: NADPH is used by enzymes in the cell that participate in catabolic pathways that produce ATP.

A Option A: NADPH is used by enzymes in the cell that have a reductive role in anabolic pathways.

Question NumberQ 1: Which one of the following polysaccharides CANNOT be digested by humans? A Option A: cellulose B Option B: glucose C Option C: starch D Option D: amylose E Option E: glycogen

A Option A: cellulose

Question NumberQ 2: The drug Gleevec is useful in the treatment of: A Option A: chronic myelogenous leukemia. B Option B: acromegaly. C Option C: heart disease. D Option D: diabetes. E Option E: influenza.

A Option A: chronic myelogenous leukemia.

Question NumberQ 3: Distinct regions of a protein that fold independently of one another are called: A Option A: domains. B Option B: hydrophobic. C Option C: alpha (​α​) helices. D Option D: side chains. E Option E: amino acids.

A Option A: domains.

Question NumberQ 1: How many electrons are in the outer shell of a carbon atom? A Option A: four B Option B: three C Option C: two D Option D: one E Option E: eight

A Option A: four

Question NumberQ 1: An oxidizing agent: A Option A: gains electrons. B Option B: loses electrons. C Option C: enters glycolysis. D Option D: is oxidized. E Option E: is typically a nutrient molecule.

A Option A: gains electrons.

Q 2: Enzymes that transfer phosphate groups between different molecules are called: A Option A: kinases. B Option B: allosteric agents. C Option C: reducing agents. D Option D: transferases. E Option E: phosphorylators.

A Option A: kinases.

Question NumberQ 2: Oxidation-reduction reactions: A Option A: occur in both catabolic and anabolic pathways. B Option B: do not occur in living organisms. C Option C: occur only in anabolic pathways. D Option D: only occur in the presence of oxygen. E Option E: occur only in catabolic pathways.

A Option A: occur in both catabolic and anabolic pathways.

Question NumberQ 3: Induced fit: A Option A: occurs in an enzyme to allow a better fit with its substrate. B Option B: indicates that an enzyme is not efficient at catalysis. C Option C: are impossible to visualize using x-ray crystallography. D Option D: may occur in a substrate allowing it to bind with an enzyme. E Option E: is a property of the enzyme-substrate complex that can stop the reaction.

A Option A: occurs in an enzyme to allow a better fit with its substrate.

Question NumberQ 4: During glycolysis, a net of how many ATP molecules are produced for each glucose that enters the pathway? A Option A: 1 B Option B: 4 C Option C: 36 D Option D: 2 E Option E: 0

D Option D: 2

Question NumberQ 2: Glycolysis requires a small initial investment of ATP because: A Option A: it activates glucose through phosphorylation. B Option B: it prepares glucose to participate in further reactions in which phosphate groups are transferred to other acceptors. C Option C: it traps glucose inside the cell. D Option D: ATP investment is required in glycolysis for all of these reasons. E Option E: it allows the cell to take up more glucose.

D Option D: ATP investment is required in glycolysis for all of these reasons.

Question NumberQ 1: Which of the following mechanisms are NOT used by cells to regulate metabolism? A Option A: Metabolic pathways are regulated by addition or removal of phosphate groups. B Option B: Metabolic pathways are regulated by altering the shape of the active site. C Option C: Enzymes are regulated by allosteric modification. D Option D: Cells modify their nutrient uptake to regulate metabolism. E Option E: Enzymes are regulated by covalent modification.

D Option D: Cells modify their nutrient uptake to regulate metabolism.

Question NumberQ 2: Which of the following statements is NOT true of enzymes? A Option A: Enzymes are usually capable of binding only one or a small number of closely related biological molecules B Option B: Enzymes can only make thermodynamically favorable reactions proceed; they cannot make unfavorable reactions occur. C Option C: Enzymes function by overcoming the activation energy barrier of a reaction. D Option D: Enzymes only function when they are in intact cells. E Option E: Enzymes are proteins that bind to specific substrates and increase the velocity of reactions involving those substrates.

D Option D: Enzymes only function when they are in intact cells.

Question NumberQ 2: The scientist who first succeeded in reconstituting complete, fully functional 30S bacterial ribosomal subunits was: A Option A: Heinz Fraenkel-Conrat. B Option B: Max Perutz. C Option C: Linus Pauling. D Option D: Masayasu Nomura. E Option E: Stanley Prusiner.

D Option D: Masayasu Nomura.

Question NumberQ 2: A sodium ion (Na+) has: A Option A: a negative charge. B Option B: lost an electron. C Option C: gained an electron. D Option D: gained a proton. E Option E: formed an anion.

Option B: lost an electron.

Question NumberQ 3: The element neon (Ne) has eight electrons in its outermost electron shell. How many covalent bonds will Ne readily form? A Option A: one B Option B: none C Option C: three D Option D: two

b none