2 - Enzymes and Bioenergetics

Question 1

Protein catalysts that increase the velocity of a chemical reaction and are not consumed during the reaction they catalyze

Answer 1

Enzymes

Question 2

Physically distinct versions of a given enzyme, each of which catalyzes the same reaction

Answer 2

Isozymes

Question 3

Catalyzes oxidations and reductions

Answer 3

Oxireductases

Question 4

Catalyze transfer of moietes such as glycosyl, methyl or phosphoryl groups

Answer 4

Transferases

Question 5

Catalyzes hydrolytic cleavage of C-C, C-O, C-N and other bonds

Answer 5

Hydrolases

Question 6

Catalyze cleavage of C-C, C-O, C-N, and other bonds by atom elimination, leaving double bonds

Answer 6

Lysases

Question 7

Catalyze geometric or structural changes within a molecule

Answer 7

Isomerases

Question 8

Catalyze the joining together of two molecules coupled to the hydrolysis of ATP

Answer 8

Ligases

Question 9

Bind in a transient, dissociable manner either to the enzyme or to a substrate

Answer 9

Cofactor

Question 10

Serve as recyclable shuttles or group transfer agents

Answer 10

Coenzymes

Question 11

Refers to enzyme only

Answer 11

APOenzyme

Question 12

Refers to enzyme + cofactor

Answer 12

HOLOenzyme

Question 13

Substrate concentration at which the reaction velocity is equal to 1/2 Vmax

Answer 13

Michaelis constant

Question 14

Maximal velocity of an enzyme-catalyzed reaction

Answer 14

Vmax

Question 15

The structure of the inhibitor resembles the substrate

Answer 15

Competitive inhibition

Question 16

The inhibitor and the substrate bind at different sites of the enzyme

Answer 16

Noncompetitive inhibition

Question 17

Increased Km

Answer 17

Competitive

Question 18

Affinity of the enzyme to the substrate is decreased

Answer 18

Competitive

Question 19

Vmax does not change

Answer 19

Competitive

Question 20

Km does not change

Answer 20

Noncompetitive

Question 21

Affinity of enzyme to the substrate does not change

Answer 21

Noncompetitive

Question 22

Vmax is lowered

Answer 22

Noncompetitive

Question 23

This equation describes how reaction velocity varies with substrate concentration

Answer 23

Michaelis-Menten Equation

Question 24

Enzymes that follow Michaelis-Menten kinetics have a

Answer 24

Hyperbolic curve

Question 25

Allosteric reactions have a

Answer 25

Sigmoid curve