4.4 Cofactors, Coenzymes and Prosthetic Groups

Question 1

What are cofactors?

Answer 1

• a non-protein component which can help an enzyme to carry out is function
• These can be obtained via diet; they are minerals
  (e. g. iron, zinc, calcium, chloride and zinc ions)

Question 2

What are coenzymes?

Answer 2

• organic molecules which help the enzyme to carry out its function (organic cofactors)
• these are derived from vitamins

Question 3

What are prosthetic groups?

Answer 3

• cofactors which bind permanently to the enzyme

- (cofactors & coenzyme = temporary, prosthetic = permanent)

Question 4

What are precursor enzymes?

Answer 4

• Enzymes which are initially inactive
• These enzymes are usually enzymes which would cause damage to the cells that produce them if they were activated, or an enzyme which needs to be controlled after certain conditions

Question 5

What is precursor activation?

Answer 5

• The activation of a precursor enzyme

- this activation causes a change in the tertiary structure

Question 6

What is an apoenzyme?

Answer 6

A precursor protein before activation

Question 7

What is a haloenzyme?

Answer 7

A precursor enzyme after activation