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Flashcards in enzymes Deck (16)
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1
Q

what do enzymes do

how

A

function as catalysts that increase rate of reaction

by lowering the activation energy

2
Q

are enzymes consumed in the reaction process

A

NO

3
Q

enzymes act on the __ in the reaction process

A

substrate

4
Q

what is the measure of affinity that an enzyme has towards the substrate

relate it to affinity

A

KM

amount of substrate required to reach 1/2 vmax

increase km, decrease affinity
decrease km, increase affinity

5
Q

what is the max velocity of the enzyme in the reaction process

A

VMAX

6
Q

what is the relationship between KM and VMAX

A

KM = 1/2 VMAX

km = x axis 
vmax= y axis 

vmax - maximal velocity of an enzyme catalyzed reaction

km - amount of substrate required to reach 1/2 vmax

7
Q

what 3 things affect the reaction velocity of an enzyme

A

substrate concentration
temperature
pH

8
Q

what are competitive inhibitors

A

competitive inhibitors - binds to substrate binding site of enzyme

increase KM (lower affinity) 
no change in Vmax
9
Q

what are non competitive inhibitors

A

non competitive inhibitors - binds to site other than substrate binding site

no change in KM (no change in affinity) 
decrease Vmax (take longer to reach full velocity)
10
Q

what can you do to competitive inhibitors to abolish its effects

A

add more substrate to dilute out the inhibitor

11
Q

what are allosteric enzymes

A

enzymes that act as rate limiting steps for metabolic processes

12
Q

phosphofructokinase is allosterically inhibited by what

A

increase ATP

13
Q

what is the measure of the amount of energy available to determine if reaction is energetically feasible

A

gibbs free energy

14
Q

what is a positive gibbs free energy mean

A

reaction is unfavorable or not spontaneous

endergonic

15
Q

what is a negative gibbs free energy mean

A

reaction is favorable or spontaneous

exergonic

16
Q

what is a = gibbs free energy mean

A

equillibrium