L26. Enzymes

Question 1

Name 2 mechanisms by which enzymes can work.

Answer 1

“lock and key”

“induced fit”

Question 2

What is the symbol and definition of free energy change?

Answer 2

delta G

The energy difference between the start and end of the reaction.

Question 3

What is the symbol and definition of activation energy?

Answer 3

Ea

Energy required to start the reaction.

Question 4

Describe the effects of enzymes on Ea and delta G.

Answer 4

Enzymes can lower Ea but not affect delta G.

Question 5

What are Vmax and Km?

Answer 5

Vmax = maximum rate of reaction

Km is a measure of affinity and is 1/2 Vmax.

Question 6

What is feedback inhibition?

Answer 6

Means a product builds up and acts as an inhibitor.

Question 7

Name the 2 types of inhibitors.

Answer 7

Competitive and non-competitive inhibitors.

Non-competitive inhibitors bind to the allosteric site.

Question 8

What do allosteric enzymes do?

Answer 8

Cause a conformational change from active to inactive or inactive to active.