Enzymes

Question 1

do not impact the thermodynamics of a biological reaction, help the reaction proceed at a much faster rate, delta Hrxn and equilibrium position do not change

Answer 1

Catalysts

Question 2

• lower the activation energy
• increase rate of reaction
• are not changed or consumed in reaction
• are pH and temp sensitive, optimal activity at specific pH ranges and temps
• do not alter the overall delta G of the reaction
• are specific for a particular reaction or class of reactions

Answer 2

Enzymes

Question 3

catalyze oxidation-reduction reactions

Answer 3

oxidoreductase

Question 4

catalyze the movement of a functional group from one molecule to another

Answer 4

transferase

Question 5

catalyze the breaking of a compound into two molecules using the addition of water

Answer 5

hydrolases

Question 6

catalyze the cleavage of a single molecule into two products

Answer 6

lyases

Question 7

catalyze the rearrangement of bonds within a molecule

Answer 7

isomerases

Question 8

catalyze addition or synthesis reaction and generally require ATP

Answer 8

ligases

Question 9

molecule upon which an enzyme acts

Answer 9

substrate

Question 10

generally inorganic molecules or metal ions

Answer 10

cofactors

Question 11

small organic groups, vast majority vitamins and derivatives or vitamins

Answer 11

coenzymes

Question 12

What is the only way to increase Vmax

Answer 12

increase [enzyme]

Question 13

describes how the rate of the reaction (v) depends on the [ E] and [S]

Answer 13

Michaelis-Menten equation

Question 14

[S] at which half of the enzyme’s active sites are full

Answer 14

Km Michaelis Constant

Question 15

double reciprocal graph of the Michaelis Menten equation, useful when determining type of inhibition enzyme is experiencing

Answer 15

Lineweaver-Burk Plot

Question 16

1/-Km

Answer 16

x intercept LBP

Question 17

1/Vmax

Answer 17

y intercept LBP

Question 18

regulation by products further down a given metabolic pathway

Answer 18

feedback regulation

Question 19

simply involves occupancy of the active site, can be overcome by adding more substrate. Increases Km

Answer 19

competitive inhibition

Question 20

bind to an allosteric site, inducing change in enzyme conformation. Cannot be overcome by adding more substrate. Decreases Vmax

Answer 20

Noncompetitive inhibition

Question 21

inhibitor can bind to either the enzyme or the enzyme-substrate complex, but has different affinity for each. Can increase or decrease Km and decreases Vmax

Answer 21

mixed inhibition

Question 22

bind only to the enzyme-substrate complex and essentially lock the substrate in the enzyme, lowers Km and Vmax

Answer 22

uncompetitive inhibition

Question 23

inactive form of enzymes, that must be altered before becoming active.

Answer 23

Zymogen

Question 24

active site is made unavailable for prolonged period of time, or enzyme is permanently altered

Answer 24

irreversible inhibition