Chapter 2

Question 1

What 2 things do enzyms do in a reaction andwhat is their structure?

Answer 1

• lower the activation energy needed for a reaction
• catalyse (speed up) reaction
  Tertiary protein

Question 2

What is the lock and key model and what is the problem with it?

Answer 2

the active site is specific to 1 substrate but evidence shows the active site can changes slightly to become fully complementary

Question 3

What is the induced fit model of enzyme action?

Answer 3

the active site changes slightly to fit the substrate and become fully complenatry

Question 4

How does temperature affect an enzymes rate of reaction?

Answer 4

• too low = not enough activation energy

- too high = denatures enzyme (breaks hydrogen, ionic and disulfide bonds on active site)

Question 5

How does pH affect the rate of enzyme action?

Answer 5

has an optimum - anything above or below denatures enzyme

Question 6

How does the concentration of enzymes and substrates affect rates of reaction?

Answer 6

• more chnace of coliision
• more active sites availiable
  increase only for a while as when all active sites are ocupied there’s no increase in rate

Question 7

What are competitive inhibitors?

Answer 7

same shape as the active site so attacht to enzymes so substrates can’t - slows rate of reaction

Question 8

What is a non-competitive inhibitor?

Answer 8

attaches to enzyme and changes the shape of its activesite so substrate can’t fit - slows rate of reaction