coenzymes and cofactors

Question 1

what are cofactors?

Answer 1

non-protein compounds required for enzyme activity
examples:
- coenzymes
- inorganic cofactors
- prosthetic groups

Question 2

what are coenzymes?

Answer 2

• organic cofactors
• do not bind permanently
• often transport molecules or electrons between enzymes
• frequently derived from water-soluble vitamins e.g. the hydrogen acceptor NAD is derived from niacin

Question 3

what are inorganic cofactors? give an example

Answer 3

• facilitate temporary binding between substrate and enzyme
• often metal ions
• e.g. Cl- is the cofactor for amylase

Question 4

what are prosthetic groups? give an example

Answer 4

• tightly bound cofactors act as a permanent part of the enzyme’s binding site
• e.g. Zn2+ for carbonic anhydrase