Models Of Enzyme Action

Question 1

Name the 2 models.

Answer 1

Lock and key model.

Induced fit model.

Question 2

What is the lock and key model?

Answer 2

This is where the substrate fits into the enzyme in the same way a key fits into a lock - they both have complementary shapes.

Question 3

What did scientists soon realise about the lock and key model ?

Answer 3

That the enzyme and substrate didn’t fit together in the first place but new evidence showed enzyme - substrate complex changed shape slightly to complete the fit.

Question 4

What is the induced fit model ?

Answer 4

The substrate doesn’t only have to be the right shape to fit into active site it has to make the active site change shape in right way.

Question 5

Which theory is the accepted one now ?

Answer 5

Induced fit model

Question 6

Enzymes can break down substrates m??

Answer 6

One substrate molecule goes into active site and 2 products come out.

Question 7

Enzymes can also synthesise substrate ?

Answer 7

2 substrates go into active site and bind together to cause one product at end.

Question 8

What happens after products are released from enzyme ?

Answer 8

Active site returns to original shape and it can then bind to next substrate molecule.