1.2.7 Enzymes

Question 1

What are enzymes?

Answer 1

Enzymes are globular proteins that act as biological catalysts

Question 2

What is the shape of an enzyme?

Answer 2

They are a 3D shape, with a depression called the active site

Question 3

Describe the lock-and-key theory

Answer 3

Molecules with a complementary shape can fit into the active site. The substrate forms temporary bonds with the amino acids, forming an enzyme-substrate complex. This produces a product, leaving the enzyme unchanged.

Question 4

Describe the induced fit theory

Answer 4

When the substrate enters the active site, the enzyme slightly changes shape, fitting more closely. When the product is released, the enzyme returns to its original shape.

Question 5

What is activation energy?

Answer 5

It is the energy needed to break bonds between molecules to start the reaction

Question 6

How do enzymes affect the activation energy?

Answer 6

Enzymes reduce the amount of activation energy needed. The active site is electrically charged, assisting the breaking of bonds.

Question 7

What happens to the rate of reaction as the enzyme concentration increases?

Answer 7

It continually increases, as more enzyme-substrate complexes are made

Question 8

What happens to the rate of reaction as the substrate concentration increases?

Answer 8

It increases until there are no more enzymes to form complexes with