BCH369 Exams 2

11. Which of the following would represent the reaction coordinate for an endergonic reaction? A) A B) B

A

A reaction is carried out in which 100 µM of substrate S is added to a mixture containing equivalent amounts of enzymes A and B. After 1 minute, which product will be more abundant? A) P C) They will be equal in concentration. B) Q D) No way to determine

A

Acetylcholine and nicotine competitively bind to nicotinic acetylcholine receptors to cause the same second messenger activation. Nicotine is considered an _______________ of the receptors. A) agonist B) antagonist C) repressor D) activator

A

Acetylcholine and nicotine competitively bind to nicotinic acetylcholine receptors to cause the same second messenger activation. Nicotine is considered an _______________ to acetylcholine. A) agonist B) antagonist C) repressor D) activator

A

An insect aminopeptidase was purified and its catalytic activity was investigated using an artificial peptide substrate. The Vmax was 4.0 x 10-7 M/s and the KM was 1.4 x 10-4 M. The enzyme concentration used in the assay was 1.0 x 10-7 M. What is the catallytic efficiency of the enzyme? A) 2.8 x 104 s-1.M-1 D) 2.9 x 10-3 s-1.M-1 B) 2.8 x 10-4 s-1.M-1 E) 3.6 x 10-3 s-1.M-1 C) 3.5 x 10-5 s-1.M-1

A

Given the plot below, which enzyme would generate product more rapidly when [S] = 1 µM? A) Enzyme A B) Enzyme B C) Enzymes A and B would generate product at the same rate.

A

In an enzyme mechanism that generates a negative charge in the transition state, which of the following would be most effective to have in the active site of the enzyme? A) transition metal cation D) transition metal anion B) Asp residue E) none of the above C) Gln residue

A

Laminaria groenlandica is a type of kelp that grows along the rocky shores of Alaska. Due to its geographic distribution, this species is subjected to cold temperatures and potential freezes. Macrocystis pyrifera is a type of kelp that grows off the coast of South America and encounters much warmer temperatures. Which of these two species would you expect to have a higher composition of unsaturated fatty acid tails incorporated into its lipid bilayer? A) Laminaria groenlandica C) They would have the same composition. B) Macrocystis pyrifera

A

Movement of the oxyanion further into the active site, where it can be preferentially bound, stabilizes the transition state of the chymotrypsin mechanism. A) True B) False

A

Some G protein-linked receptors are associated with a protein called RGS (regulator of G protein signaling). RGS stimulates the GTPase activity of the G protein associated with the receptor. What effect does RGS have on the signaling process? A) This will shorten the duration of signaling. B) This will lengthen the duration of signaling. C) Since the G protein has inherent GTPase activity -- this will have no effect on signaling.

A

The Na,K-ATPase is a(n) _____ that moves Na+ from _____ and K+ from _____. A) antiporter; inside to out; outside to in D) symporter; outside to in; outside to in B) antiporter; outside to in; inside to out E) none of the above C) symporter; inside to out; inside to out

A

Under certain conditions, peptide bond formation is more thermodynamically favorable than peptide bond hydrolysis. Would you expect chymotrypsin to catalyze peptide bond formation? A) Yes B) No C) Cannot be determined

A

What is the relationship between KM and [S] when an enzyme-catalyzed reaction proceeds at 90% of Vmax? A) [S] = 9 KM B) [S] = 0.9 KM C) [S] = KM D) [S] = 0.10 KM E) [S] = 10 KM

A

Which amino acid in the aquaporin channel hydrogen bonds with water to prevent the movement of protons? A) Asn B) Leu C) Phe D) Val E) Ile

A

Which is not a consequence of the cis double bonds of fatty acids? A) A higher melting temperature B) A rigid 30o bend in the hydrocarbon chain C) Reduced van der Waals interactions among chains D) Less efficient packing of the hydrocarbon chains

A

Which of the following second messengers would NOT be found free floating in the cytosol? A) DAG B) Ca2+ ions C) cAMP D) IP3

A

Which of the following types of proteins pass through both leaflets (monolayers) of the membrane? A) integral membrane proteins D) both A and C B) peripheral proteins E) all of the above C) lipid-linked proteins

A

Which of the following would represent the reaction coordinate for a two-step reaction with an initial slow step? A) A B) B

A

Which type of secondary structure present in integral membrane proteins is readily detectable in the primary structure? A) membrane-spanning α helix B) membrane-spanning β sheet

A

A mutation in the active site of an enzyme results in a large increase in stabilization of the ES complex, while there is no change in the stabilization of the transition state complex. What effect will this have on the rate of product formation? A) No effect B) Decrease rate C) Increase rate

B

A patient suffers from premature zymogen activation, so that the pancreatic enzymes are activated in the pancreas rather than the small intestine -- causing damage to the pancreas. Which of the following would be the most effective in preventing these effects? A) chymotrypsin inhibitor B) trypsin inhibitor C) elastase inhibitor

B

A typical β barrel transmembrane protein contains ____ β strands. A) 1-7 D) Any of the above B) 8-22 E) None of the above C) 23-36

B

Activation of a G protein in response to hormone binding requires binding of _____ to the _____ subunit. A) GDP; β B) GTP; α C) GDP; γ D) GTP; β E) GDP; α

B

An enzyme has two inhibitors with KI values of 2 mM and 2 µM. Which is the more potent inhibitor? A) KI = 2 mM B) KI = 2 µM

B

Glucose is added to cells and the rate of glucose transport is plotted against glucose concentration. In the presence of the galactose derivative 6-O-benzyl-D-galactose the curve is shifted to the right (with no other change). What kind of agent is this galactose derivative? A) Activator D) Mixed inhibitor B) Competitive inhibitor E) None of the above C) Noncompetitive inhibitor

B

Hexokinase undergoes a large conformational change in order to exclude water from the active site. Would chymotrypsin undergo such a change upon binding its substrate? A) Yes B) No

B

Phospholipase C cleaves phosphatidylinositol bisphosphate (PIP2) generating A) cAMP + PPi (inorganic pyrophosphate) B) IP3 + DAG (inositol trisphosphate + diacylglycerol) C) IP3 + PPi D) cAMP + DAG E) IP3 + Pi (inorganice phosphate)

B

Plants can synthesize trienoic acids (fatty acids with 3 double bonds) by introducing another double bond into a dienoic acid. Would you expect plants growing at higher temperatures to convert more or less of their dienoic acids into trienoic acids? A) They would convert more. C) There would be no difference. B) They would convert less.

B

Prodrugs are inactive compounds that need to be cleaved in order to yield an active drug. A novel tumor therapy has recently involved the delivery of an enzyme, capable of catalyzing this cleavage reaction, to the tumor site. This is followed by administration of the prodrug, which in this instance is acting as the substrate. Suppose that there are two enzymes capable of catalyzing this reaction. Enzyme A has a KM for the prodrug of 1 µM and Enzyme B has a KM of 1 nM. Which enzyme would you use in patients? A) Enzyme A B) Enzyme B

B

Rank the melting points of the following fatty acids. 1) cis-oleate (18:1) 2) trans-oleate (18:1) 3) linoleate (18:2) A) 1 > 2 > 3 D) 3 > 1 > 2 B) 2 > 1 > 3 E) None of the above C) 2 > 3 > 1

B

The concentration of cytosolic Ca2+ is the extracellular concentration. A) dependent upon D) greater than B) less than E) linearly related to C) the same as

B

The rate constant associated with the reaction below would be A --> B + C A) Zero order B) First order C) Second order D) Third order

B

The steady state for enzyme kinetics assumes A) The amount of product will decrease during the reaction. B) The rate of formation of [ES] is equal to the rate of consumption over the course of the reaction. C) The rate of formation of [ES] exceeds the rate of consumption over the course of the reaction. D) Substrate concentration will increase during the reaction.

B

The total concentration of receptors in a sample is 20 mM. The concentration of free ligand (L) is 5 mM and Kd is 10 mM. Calculate the percentage of receptors that are occupied by ligand. A) 67% B) 33% C) 25% D) 75% E) 50%

B

What is the major factor in determining the types of secondary structures that form in the transmembrane portions of integral membrane proteins? A) Maximizing van der Waals contacts between lipid acyl chains B) Hydrogen bonding interactions of protein backbone groups C) Ionic interactions of amino acid side chains D) Hydrophobic interactions of amino acid side chains

B

Which of the following amino acids could bind to the specificity pocket of Trypsin? A) Gly B) Lys C) Asp D) Gln E) Val

B

Which of the following is true regarding the glucose transporter? A) in addition to glucose, it will transport any other monosaccharide with six carbons B) binding of glucose causes a conformational change so that the transporter is never open on both sides of the membrane C) ATP hydrolysis prevents the transporter from working in reverse D) it is able to transport glucose into a cell against a concentration gradient E) none of the above

B

Which of the following statements about the mechanism of the Na+ /K+ ATPase pump is correct? A) In the Na+ /K+ ATPase reaction cycle, Na+ is pumped into the cell when the protein is dephosphorylated. B) In the Na+ /K+ ATPase reaction cycle, Na+ is pumped out of the cell when the protein is phosphorylated. C) In the Na+ /K+ ATPase reaction cycle, Na+ is pumped into the cell when the protein is phosphorylated. D) In the Na+ /K+ ATPase reaction cycle, Na+ is pumped out of the cell when the protein is dephosphorylated

B

Which of the following terms describes all glycerophospholipid? A) zwitterionic D) amphoteric B) amphipathic E) none of the above C) nonpolar

B

Would a homopolymer of alanine be more likely to form an α helix in water or in a hydrophobic medium? A) Water B) Hydrophobic medium

B

6. How many acyl chains are present in glycerophospholipids? A) 0 B) 1 C) 2 D) 3

C

A membrane consisting only of phospholipids undergoes a sharp transition from the crystalline form to the fluid form as it is heated. What would be the effect on this transition in a membrane containing 80% phospholipid and 20% cholesterol? A) The same sharp transition would be observed, but the melting temperature would be lower. B) The same sharp transition would be observed, but the melting temperature would be higher. C) The shift from the crystalline to the fluid form would be more gradual. D) It would depend on the type of phosphilipid present.

C

A molecule moves across a membrane from a lower to a higher concentration with the aid of a membrane protein. This process is known as: A) chemiosmotic coupling C) active transport B) diffusion D) facilitated transport

C

ABC transporters are examples of A) passive diffusion D) secondary active transport B) facilitated transport E) tertiary active transport C) primary active transport

C

Alcohol dehydrogenase (ADH) converts ethanol into acetaldehyde in the liver. The acetaldehyde is then processed by acetaldehyde dehydrogenase (ALDH) to form acetic acid, according to the scheme below. Following ingestion of a large volume of ethanol, all all of the acetaldehyde cannot be processed and builds to concentrations that result in the physiological symptoms of intoxication. The ALDH enzyme is inhibited by the compound benzaldehyde (below). ALDH has a native KM for acetaldehyde of 160 µM and a Vmax of 1.4 µmol/min, with a KI for benzaldehyde of 0.18 µM. Calculate the initial velocity (v0) expected when the ALDH assay is conducted using 48 µM of acetaldehyde in the presence of 4.2 µM benzaldehyde. A) 0.028 µmol/min D) 0.007 µmol/min B) 0.31 µmol/min E) 1.3 µmol/min C) 0.017 µmol/min

C

Allosteric enzymes A) have only one active site B) are regulated by covalent modification C) usually have more than one polypeptide chain D) catalyze several different reactions within a metabolic pathway E) all of the above

C

Glucose is mobilized for ATP generation in muscle in response to epinephrine. Cyclic AMP phosphodiesterase is an enzyme that converts cAMP to AMP. How would inhibitors of cAMP phosphodiesterase affect glucose mobilization in muscle? A) These inhibitors would decrease glucose mobilization. B) These inhibitors would have no effect on glucose mobilization. C) These inhibitors would increase glucose mobilization.

C

Glutamate acts as a neurotransmitter in the brain. The Glu transporter also transports 3 Na+ and 1 H+ along with Glu and 1 K+ in the opposite direction. What is the net charge imbalance across the cell membrane for each Glu transported at physiological pH? A) +4 B) +3 C) +2 D) +1 E) 0

C

Glycosphingolipids with complex carbohydrate head groups that often serve as cellular receptors are A) cerebrosides D) eicosanoids B) steroids E) sphingomyelin C) gangliosides

C

How does the addition of an enzyme to a chemical reaction affect the standard free energy of the reaction? A) Increases it B) Decreases it C) No effect

C

In the reaction mechanism of the glycolytic enzyme aldolase, an active site tyrosine residue accepts a proton from the substrate. In this form the side chain of Tyr must be _________ and it is acting as a(n) __________ catalyst. A) protonated; acid B) deprotonated; acid C) deprotonated; base D) protonated; base

C

Inside a nerve cell at rest, [Na+] is _____ and [K+] _____ relative to the concentrations seen outside the cell. A) high; high B) high; low C) low; high D) low; low E) low; equal

C

It is necessary to know the value of [E]t in order to determine the values of A) KM B) Vmax C) kcat D) B and C E) A, B and C

C

Kinetic studies are carried out for a Michaelis-Menten enzyme at a specific concentration of enzyme. What would be the effect on KM and Vmax if twice as much enzyme is used? A) No change in either KM or Vmax. C) Vmax will double but KM will remain the same. B) Both KM and Vmax will double. D) KM will double but Vmax will remain the same.

C

Ligand binding to a receptor tyrosine kinase causes _____ of the receptor which then _____ the next protein in the signaling pathway. A) methylation; hydrolyzes D) acylation; activates B) hydrolysis; inhibits E) none of the above C) phosphorylation; phosphorylates

C

On a Lineweaver-Burk plot, the intercept where 1/[S] = 0 is A) -1/KM B) KM C) 1/Vmax D) Vmax E) kcat

C

Phorbol esters, which are compounds isolated from plants, are structurally similar to diacylglycerol. How does the addition of phorbol esters affect the signaling pathways of cells in culture? A) They would elevate the concentration of cAMP. B) They would activate protein kinase A. C) They would activate protein kinase C. D) They would activate Ras protein. E) They would stimulate lipid hormone signaling.

C

Sarin gas [(CH3)2CHO]CH3P(O)F is a fatal nerve agent that acts as an irreversible inhibitor of the enzyme acetylcholine esterase. Acetylcholine esterase hydrolyzes acetylcholine to render it inactive in the synapse. Atropine is an antagonist to acetylcholine. Latrotoxins (black widow venom) act as agonists to acetylcholine. Which of the following physiological features would you expect to find in an individual exposed to sarin gas? Would you treat this individual with atropine or latrotoxins to reverse the symptoms? A) Increased muscle contraction; latrotoxin C) Increased muscle contraction; atropine B) Decreased muscle contraction; latrotoxin D) Decreased muscle contraction; atropine

C

The activity of chymotrypsin changes as the pH changes in the range of pH 5 to pH 9. From your understanding of the chemical mechanism of the chymotrypsin reaction, answer the following questions: 1) which amino acid is most likely responsible for the effect of pH?; and 2) would the activity likely increase, decrease, or remain the same as the pH increases? A) Asp; activity increases with pH D) His; activity decreases with pH B) Ser; activity decreases with pH E) Ser; activity increases with pH C) His; activity increases with pH

C

The rate constant associated with the reaction below would be 2A --> B A) Zero order B) First order C) Second order D) Third order

C

The reaction catalyzed by glyceraldehyde-3-phosphate dehydrogenase is given below. To which class does the enzyme belong? A) Transferase D) Hydrolase B) Isomerase E) Lyase C) Oxidoreductase

C

Which of the following curves shows the appropriate relationship between [ES] and time in steady state kinetics? A) (a) B) (b) C) (c) D) (d) E) (e)

C

Which of the following is FALSE regarding transition state stabilization? A) An enzymatic catalyst makes formation of the transition state more favorable. B) An enzymatic catalyst lowers the energy of the transition state. C) Transition state stabilization refers to the shift in the equilibrium of the reaction. D) Enzyme cofactors are often used to stabilize transition state molecules. E) Stabilization of the transition state results in a greater reaction velocity.

C

Which of the following lipid types are not found in animal membranes? A) phosphoglycerides D) glycolipids B) cholesterol E) sphingolipids C) triacylglycerols

C

Which of the following pathways would provide the slowest response to an extracellular signal? A) phosphorylation events B) activation through second messengers C) lipid hormone-mediated control of gene expression

C

Which of the following statements regarding membrane transporters is TRUE? A) A porin is always open but only transports solutes in one direction. B) An ion channel selective for K+ will also allow Na+ through since both are small enough to fit through the channel. C) K+ and Na+ channels are examples of uniporters. D) K+ channels work in both directions, allowing the neuronal action potential to move in multiple directions. E) None of the above are true.

C

Which of the following statements regarding the phosphoinositide signaling pathway is FALSE? A) Diffusion of inositol trisphosphate in the cytoplasm results in the opening of Ca2+ channels. B) The influx of Ca2+ intiates a kinase cascade. C) Diacylgycerol interacts directly with protein kinase A and sequesters it at the membrane. D) Diacylgycerol interacts with a cellular protein that requires Ca2+ for full activation. E) The downstream effects of Ca2+ influx is most often mediated by the calcium-binding protein calmodulin.

C

Yeast glucose-6-phosphate dehydrogenase can be inhibited by a number of cellular agents whose KI values are listed below. Which is the most effective inhibitor? Which inhibitor is likely to be completely ineffective under normal cellular conditions? Inhibitor KI (M) Inorganic phosphate 1.0 x 10-1 Glucosamine-6-phosphate 7.2 x 10-4 NADPH 2.7 x 10-5 A) Most effective: inorganic phosphate; Ineffective: NADPH B) Most effective: glucosamine-6-phosphate; Ineffective: NADPH C) Most effective: NADPH; Ineffective: inorganic phosphate D) Most effective: NADPH; Ineffective: glucosamine-6-phosphate E) Most effective: glucosamine-6-phosphate; Ineffective: inorganic phosphate

C

28. The structure of the drug prednisone is shown below. What is the most likely means of transport of this molecule into the cell? A) Binds to cell surface receptor C) Moves by antiport or symport B) Moves through a gated channel D) Simple diffusion

D

A small molecule produced inside a cell in response to a hormone binding to its receptor is called a(n) _____. A) inside messenger D) second messenger B) agonist E) G protein C) antagonist

D

All known porins are _____ proteins composed of _____. A) monomeric; seven transmembrane α-helices D) trimeric; β-barrels B) dimeric; β-barrels E) trimeric; four transmembrane α-helices C) dimeric; three transmembrane α-helices

D

An enzyme has an active site at which it can bind and hydrolyze either X or Y, though it cannot bind both at the same time. How will the KM and Vmax for X be affected if Y is present in the reaction mixture? A) The KM will increase and the Vmax will decrease. B) The KM will decrease and the Vmax will increase. C) Both the KM and the Vmax will decrease. D) The KM will increase and the Vmax will not change. E) Both the KM and the Vmax will increase.

D

Bacillus anthracis, the cause of anthrax, produces a three-part toxin. One part facilitates the entry of the two other toxins into the cytoplasm of a mammalian cell. The toxin known as edema factor (EF) is an adenylate cyclase. What is the effect of this toxin? A) The levels of DAG rise and protein kinase C is activated. B) The levels of Ras rise and gene expression is elevated. C) The levels of Ca2+ rise and protein kinase C is activated. D) The levels of cAMP rise and protein kinase A is activated.

D

In some environments, phospholipids can form "inside-out" membranes -- where the hydrophilic heads are on the interior of the structure and the hydrophobic tails interact with the solvent. In which solvent would this most likely happen? A) Water B) Ammonia C) Ethanol D) Benzene

D

Renin or chymosin is a protease similar to chymotrypsin, except that it belongs to a class of enzymes called aspartyl proteases -- in which asparatate residues are found in the active site rather than serine. Renin catalyzes the hydrolysis of a peptide bond in the protein angiotensinogen, converting it to angiotensin I, a precursor of a hormone involved in regluating blood pressure. Renin inhibitors are therefore potentially valuable in the treatment of high blood pressure. Two aspartate residues in the renin active site, Asp 32 and Asp 215, constitute a catalytic dyad, rather than the catalytic triad found in chymotrypsin. Given this information and the figure below, what type of catalysis is utilized by renin? Which of the two active site Asp residues will have the lower pK value? A) Renin uses acid-base catalysis; Asp 215 has the lower pK value B) Renin uses covalent catalysis; Asp 32 has the lower pK value C) Renin uses covalent catalysis; Asp 215 has the lower pK value D) Renin uses acid-base catalysis; Asp 32 has the lower pK value E) Renin uses metal ion catalysis; Asp 32 has the lower pK value

D

The GLUT transporter moves glucose through a transport protein in the same direction as its concentration gradient. The action of the glucose transporter is an example of _____________. The SGLT transporter uses the sodium concentration gradient created by the sodium potassium ATPase to move glucose against its concentration gradient. The action of the SGLT transporter is an example of _______________. A) facilitated transport, primary active transport B) diffusion, secondary active transport C) facilitated transport, facilitated transport D) facilitated transport, secondary active transport E) None of the above choices are corret.

D

The chymotrypsin/trypsin family of proteases has which combination of amino acids in the active site A) threonine, histidine, aspartic acid D) serine, histidine, aspartic acid B) serine, arginine, glutamic acid E) threonine, histidine, aspartic acid C) serine, histidine, glutamic acid

D

The complex formed between a lipid hormone and its receptor binds to _____ which are specific DNA sequences. A) transcription factors D) hormone response elements B) nuclear localization sequences E) none of the above C) DNA-binding domains

D

The drug known as Botox is a preparation of botulinum toxin. How does this account for its use by plastic surgeons to alleviate facial wrinkles? A) botulinum toxin targets SNAREs for degradation by proteolysis. B) SNAREs are necessary for transmission of signals from facial nerves to muscles via synaptic. C) SNAREs function by forming α−helical bundles to fuse synaptic vesicles with the plasma membrane D) all of the above E) none of the above

D

The kinetics of an enzyme is measured as a function of substrate concentration in the presence and absence of 100 µM inhibitor and the data plotted as in the graphs below. Based on these data, answer the following questions: 1) what type of inhibition is indicated; and 2) what is the dissociation constant of this inhibitor? A) Competitive inhibitor; KI = 25 µM D) Noncompetitive inhibitor; KI = 25 µM B) Uncompetitive inhibitor; KI = 4.0 µM E) Competitive inhibitor; KI = 4.0 µM C) Mixed inhibitor; KI = 30 M

D

There are few examples of inhibitors that decrease Vmax but do not affect KM, these inhibitors A) affect kcat B) affect the catalytic function, but not the binding of substrate C) are called noncompetitive D) all of the above E) none of the above

D

Where are the ultimate targets of the Ras-dependent signaling cascade located within the cell? A) cytoplasm D) nucleus B) mitochondria E) cell membrane C) endoplasmic reticulum

D

Which of the following amino acid residues would NOT provide a side chain for acid-base catalysis? A) lysine B) threonine C) glutamic acid D) valine E) histidine

D

Which of the following statements about allosteric control of enzymatic activity is false? A) Allosteric effectors give rise to sigmoidal V0 vs. [S] kinetic plots. B) Allosteric enzymes are usually multi-subunit complexes. C) An effector may either inhibit or activate an enzyme. D) Binding of the effector to the active site changes the conformation of the enzyme molecule. E) Allosteric regulators are often a downstream product of the pathway.

D

Which of the receptors below is a tyrosine kinase? A) β2-adrenergic receptor C) phospholipase C receptor B) G protein receptor D) insulin receptor

D

cAMP binds to the _____ subunits of protein kinase A allowing the tetramer to dissociate into _____. A) active subunits; an active dimer and two inactive monomers B) active subunits; two active monomers and an inactive dimer C) regulatory subunits; an active dimer and two inactive monomers D) regulatory subunits; two active monomers and an inactive dimer E) regulatory subunits; two active monomers and two inactive monomers

D

A pH/rate curve with an inflection point at pH~4 suggests the involvement of a(n) ________ in the catalytic step. A) redox cofactor D) hydrophobic amino acid B) basic amino acid E) acidic amino acid C) metal ion

E

Based on the reaction below, how would the enzyme catalyzing this reaction be classified? A) Oxidoreductase D) Ligase B) Hydrolase E) Transferase C) Lyase

E

If an enzyme-catalyzed reaction with a KM of 3.5 mM has a velocity of 5 mM/min at a substrate concentration of 0.5 mM, what is the Vmax? A) 0.625 mM/min D) 35 mM/min B) 15 mM/min E) 40 mM/min C) 17.5 mM/min

E

The movement of glucose into a cell when blood sugar is high is accomplished by _____. The movement of K+ against its concentration gradient is accomplished by _____. A) simple diffusion; active transport D) simple diffusion; passive transport B) passive transport; passive transport E) passive transport; active transport C) active transport; membrane potential

E

What is the membrane potential created by a sodium gradient where [Na+]out = 145 mM and [Na+]in = 12 mM at 37°C? A) 67 mV B) 7.9 mV C) -7.9 mV D) -29 mV E) -67 mV

E

Which of the following curves shows the appropriate relationship between enzyme velocity and enzyme concentration? A) (a) B) (b) C) (c) D) (d) E) (e)

E

Which of the following will cause the opening or closing of a gated ion channel? A) pH change D) ligand binding B) phosphorylation E) all of the above C) voltage change

E

Which of the following would be a proper representation of enzyme velocity? A) v = (-) d[P]/dt D) v = (+) d[S]/dt B) v = (+) d[P]/dt E) Either B or C C) v = (-) d[S]/dt

E