29) In the Lineweaver-Burk plot of an enzyme reaction, the Km is given by the _.
C) negative reciprocal of the x-intercept
D) reciprocal of the y-intercept
30) The Lineweaver-Burk plot and other lin
29) The graphs below all represent the same chemical reaction, but each employing a different
catalyst. Which enzyme uses the most efficient mechanism of catalysis?
A) see graph I
B) see graph II
C) see graph III
D) see graph
62) Water can easily penetrate and even pass through the interior of a folded protein.
63) Proline exists in the cis configuration more frequently than any other amino acid.
64) All amino acids
80) Heat shock proteins are those stable at higher temperatures.
81) Ascorbic acid is necessary for the formation of hydroxyproline and hydroxylysine residues
before they are incorporated into the collagen protein molecule.
For each term select the description that best describes its contribution to the structure of collagen.
A) Has H bonds which help stabilize
B) Makes the protein rigid
C) Required for
13) In an enzyme reaction involving one enzyme and one substrate, the rate of the reaction depends
A) substrate concentration.
B) enzyme concentration.
C) both substrate and enzyme concentrations.
D) the enzyme concentration at first and the substrate
21) The expression: V max = k2 [E]total applies to
A) zero order kinetics of an enzyme-catalyzed reaction.
B) first order kinetics of an enzyme-catalyzed reaction.
C) second order kinetics of an enzyme-catalyzed reaction.
D) only the initial part (near ti
37) What distinguishes reversible inhibitors from irreversible inhibitors?
A) Reversible inhibitors are not covalently bound to enzymes but irreversible inhibitors are.
B) There is an equilibrium between bound and unbound reversible inhibitor. There usual
5) Most of the known enzymes are _.
6) An enzyme that catalyzes conversions of L-sugars to D-sugars is called a/an _.
Select the correct class of enzyme for each of these reactions.
74) L-Glutamate + ATP + NH4 +
L-glutamine + ADP + Pi
75) L-aspartic acid +
acid + L-Glutamate
6) A chemical group that has a negative charge or an unshared electron pair is called a(an)
A) transition state
7) Cleavage of a C-C bond produces a carbanion that _ both electrons a
59) In a multienzyme complex the process of directly transferring a product of one reaction to the
next active site without allowing it to enter the bulk solvent is termed _.
A) a ping-pong reaction
B) metabolite channeling
C) the activity pathway
50) Allosteric modulators seldom resemble the substrate or product of the enzyme. What does this
A) Modulators likely bind at a site other than the active site.
B) Modulators always act as activators.
C) Modulators bind non-covalently to
13) On the energy diagram below, which arrow(s) represent the activation energy for the forward
and reverse reactions?
A) Arrow 1 is the activation energy for both the forward and reverse reactions.
B) Arrow 1 is the activation energy for the forward reac
25) Which graph might you expect for the pH profile of an enzymes activity if the only ionizable
residue in the active site is aspartate?
26) An enzymes active site contains an arginine residue and a g
19) The following pH dependence was found for the activity of a certain enzyme-catalyzed
If it is known that the only two ionizable residues in the active site are both glutamates, which
conclusion can be drawn?
A) The glutamates have different
53) The main property of myoglobin and hemoglobin that makes them an efficient system for
oxygen delivery from lungs to muscles is
B) different binding affinities for oxygen.
C) movement of the protein shapes.
E) All o
46) Which statement is false about allosteric regulation?
A) It is usually the mode of regulation for the last step in reaction pathways since this step
produces the final product.
B) Cellular response is faster with allosteric control than by controlling
45) The Tm of a protein is temperature at which it
A) is completely denatured.
C) is half denatured.
D) resists denaturation.
46) Proteins with high Tm values are generally stable at
A) room temperature (21 C).
42) What type of inhibition is indicated by the data graphed below?
43) The following data were obtained in the presence and absence of inhibitor. What type of