enzyme kinetics

Question 1

difference between a cofactor and a coenyme

Answer 1

cofactors don’t get used up but coenzymes do

Question 2

what enzyme is an example of an induced fit

Answer 2

hexokinase

Question 3

what is Km

Answer 3

substrate conc where enzyme velocity is 1/2 max

Question 4

what is Kcat

Answer 4

describes the rate limiting step of any enzyme catalyzed faction, turnover number aka measure of substrate molecules turned over per enzyme molecule per second

Question 5

three kinds of reversible inhibitors

Answer 5

competitive uncompetitive mixed

Question 6

what does competitive inhibitor bind

Answer 6

e

Question 7

what does uncompetitive inhibitor bind

Answer 7

ES copmlex

Question 8

what does a mixed inhibitor bind

Answer 8

both E and ES complex

Question 9

what type of an inhibitor is a noncompetitive inhibitor

Answer 9

mixed

Question 10

what ratio do you use to compare enzymes

Answer 10

Kcat/Km

Question 11

competitive inhibition- what happens to kcat and km

Answer 11

kcat doesn’t change and apparent Ck increases as [I] increases

Question 12

in lineweaver burk plot, what is the x and y intercept and slope indicative of

Answer 12

x intercept= -1/Km, y intecept= 1/vmax, and slope is Km/Vmax

Question 13

in mixed inhibition, what parameters are affected

Answer 13

All-kcat, vmax, and Km

Question 14

in uncompetitive inhibitors, what parameters are affected

Answer 14

all three

Question 15

regulation of enzymes 4 mechanisms

Answer 15

allosteric, covalent modification, binding of another reg protein, proteolytic cleavage for actuation