Enzyme Kinetics 3

Question 1

What is the non-competitive inhibition case study?

Answer 1

alanine non-competitively inhibits pyruvate kinase

Question 2

What occurs in the alanine case study?

Answer 2

• alanine is one product of a series of enzyme-catalysed reactions
• 1st step: catalysed by phosphenol kinase

Question 3

What does alanine act as?

Answer 3

negative allosteric modulator

Question 4

What slows down the production of alanine when in excess?

Answer 4

negative feedback loop

Question 5

In pyruvate fructokinase, the active site and inhibitor sites are in…?

Answer 5

different places

Question 6

What are the 2 components of an holoenzyme?

Answer 6

• apoenzyme

- cofactor

Question 7

What are cofactors derived from?

Answer 7

vitamins

Question 8

When a cofactor is tightly bound to an enzyme, what is it called?

Answer 8

prosthetic group

Question 9

What is usually a cofactor?

Answer 9

metals

Question 10

What are 4 fat-soluble vitamins?

Answer 10

A,D,E,K

Question 11

What is the function of vitamin A?

Answer 11

• vision, growth, reproduction

Question 12

What is the function of vitamin D?

Answer 12

• regulation of calcium and phosphate metabolism

Question 13

What is the function of vitamin E?

Answer 13

• antioxidant

Question 14

What is the function of vitamin K?

Answer 14

• blood coagulation

Question 15

In allosteric enzyme kinetics, Vo is dependent on [S], but what can the curve be described as?

Answer 15

sigmoidal

Question 16

Substrate binding may be…?

Answer 16

cooperative

Question 17

Define “cooperativity”

Answer 17

binding of a substrate at one site affects the affinity for the other

Question 18

What is “positive cooperativity”?

Answer 18

the binding rate of the second S is increased

Question 19

What is “negative cooperativity”?

Answer 19

the binding rate of the second S is decreased