Enzyme Action

Question 1

What types of protein are enzymes?

Answer 1

Enzymes are globular proteins

Question 2

What are globular proteins?

Answer 2

Protein molecules where the tertiary structure has given the molecule a generally rounded, ball shape

Question 3

Describe what an enzyme is:

Answer 3

Enzymes are globular proteins, that act as catalysts

Question 4

What are catalysts?

Answer 4

Catalysts are substances that alter the rate of a chemical reaction without undergoing permanent changes themselves

Question 5

How many times can you use an enzyme?

Answer 5

Enzymes can be used repeatedly, therefore making them effective in small amounts

Question 6

What can enzymes do/not do?

Answer 6

Enzymes can lower the activation energy in reactions, therefore allowing reactions to take place at lower temperatures and speeding them up.

They do not however, make reactions happen

Question 7

What are the conditions required for a chemical reaction to occur?

Answer 7

1. Molecules must collide with sufficient energy in order to alter the arrangement of their atoms to form their products
2. The free energy of the products must be less than that of the substrates
3. An initial amount of energy (activation energy)

Question 8

What is the meaning of activation energy?

Answer 8

The minimum amount of energy needed to activate a chemical reaction

Question 9

What is the structure of an enzyme?

Answer 9

Enzymes have a specific 3D shape and a specific region which is functional. This is known as the active site.

Question 10

What are the differences between the lock and key model/induced fit model?

Answer 10

Induced fit model: active site is almost complementary to the substrate but changes shape slightly to fit the substrate

Lock and key model: the active site is a fixed shape and the substrate attaches, when complementary, due to random collisions