Enzymes at work - Coenzyme and Prosthetic Group

Question 1

What is a cofactor?

Answer 1

• A cofactor is any substance that must be present to ensure enzyme-controlled reactions to take place at the appropriate rate.

Question 2

What are coenzymes?

Answer 2

• Coenzymes often carry chemical groups between enzymes so they link enzyme-controlled reactions together in a sequence.

Question 3

What does Vitamin B do and what does an absence of it result in?

Answer 3

• Vitamin B (Nicotinamide) plays an important role in breaking down fats/carbohydrates to release energy. Vitamin B makes coenzyme that is required for enzyme pyruvate dehydrogenase. This catalyses a reaction stage in respiration. Pellagra develops with deficiency.

Question 4

What is a prosthetic group and what do they do?

Answer 4

• A coenzyme that is a permanent part of an enzyme molecule is a prosthetic group. Vital to the function of the enzyme (protein) molecule – contribute to shape and charges.

Question 5

What does carbonic anhydrase contain?

Answer 5

Carbonic anhydrase contains a zinc-based prosthetic group.

Question 6

How can ions increase the reaction rate?

Answer 6

• Ions can increase reaction rate, by combining with enzyme/substrate. Makes enzyme-substrate complex form more easily, as effects charge distribution and shape of complex.

Question 7

When does amylase work?

Answer 7

Amylase only works if chloride ions are present.