02. 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

classes of enzymes

Answer 2

oxidoreductases
transferases
hydrolases
lyases
isomerases
ligases

Question 3

properties of enzymes

Answer 3

active site
efficient
specific
require cofactors

Question 4

bind in a transient dissociable manner either to the enzyme or to a substrate

Answer 4

cofactor

Question 5

serve as recyclable shuttles - or group transfer agents - that transport many substrats from their point of generation to their point of utilization

Answer 5

coenzyme

Question 6

enzymes work by

Answer 6

lowering the free energy of activation

Question 7

enzymes that follow michaelis-menten kinetics have a ________ curve

Answer 7

hyperbolic

Question 8

____ Km has _____ substrate affinity

Answer 8

HIGH Km = LOW substrate affinity

LOW Km = HIGH substrate affinity

Question 9

Above Km

Answer 9

zero order kinetics

rate not affected by [S]

Question 10

Below Km

Answer 10

first order kinetics

rate directly proportional to [S]

Question 11

increase in temperature =

Answer 11

increase in reaction rate

Question 12

very high temperature =

Answer 12

decrease in reaction rate due to denaturation

Question 13

reciprocal of the michaelis menten equation

Answer 13

lineweaver burk plot

Question 14

lineweaver burk plot

Answer 14

used to calculate Km and Vmax

Question 15

Competitive inhibition:
mechanism
reversal
Km
Vmax

Answer 15

Competitive inhibition:
mechanism - competes for binding site
reversal - increase [S]
Km - increased
Vmax - not changed

Question 16

Non-competitive inhibition:
mechanism
reversal
Km
Vmax

Answer 16

Non-competitive inhibition:
mechanism - bind somewhere else
reversal - increase [E]
Km - not changed
Vmax - lowered

Question 17

kinase

Answer 17

attach phosphatase

Question 18

phosphokinase

Answer 18

remove phosphatase

Question 19

ΔG

Answer 19

net loss of energy (exergonic)

spontaneous reaction

Question 20

ΔG > 0

Answer 20

net gain of energy (endergonic)

not a spontaneous reaction

Question 21

ΔG = 0

Answer 21

equilibrium

forward and backward reactions are equal

Question 22

ΔG

Answer 22

standard free energy change

Question 23

Enthalpy -
Entropy +

Spontaneous?

Answer 23

YES. Always

Question 24

Enthalpy +
Entropy -

Spontaneous?

Answer 24

NO. Always

Question 25

Enthalpy +
Entropy +

Spontaneous?

Answer 25

MAYBE, but only at high temperatures

Question 26

Enthalpy -
Entropy -

Spontaneous?

Answer 26

MAYBE, but only at low temperatures

Question 27

greatest quantitative source of high energy phosphate in aerobic organisms

Answer 27

oxidative phosphorylation

Question 28

In glycolysis, ATP is generated in 2 steps

Answer 28

1,3 BPG + ADP -> 3PG + ATP (physphoglycerate kinase)

PEP + ADP -> pyruvate + ATP (pyruvate kinase)

Question 29

in the citric acid cycle, ATP is generated in 1 step

Answer 29

syccinyl CoA + ADP > succinate + ATP (succinyl thiokinase)

Question 30

2 electron carriers used in ETC

Answer 30

NAD

FAD

Question 31

NAD is derived from which vitamin

Answer 31

niacin B3

Question 32

FAD is derived from which vitamin

Answer 32

riboflavin B2