Question

1. What is the difference between catabolism, anabolism, and metabolism? 2. What is an enzyme? 3. Differentiate between apoenzyme and holoenzyme. 4. A)What is the function of an enzyme? B)What type of reactions are they involved in?

Answer 1

1. a) Catabolism can be defined as a certain set of pathways in our metabolism which are involved in breaking of molecules into smaller parts. This is done either to extract energy from them or to use them in other anabolic reactions to build other required molecules.

b) Anabolism is the opposite of the above. It involves formation of larger molecules from smaller one's and this is done to ensure energy storage.

c) Metabolism is defined as chemical reactions that occur in organisms or a set of these reactions that occur inside a cell of organisms in order to maintain life.

2. In context of biology, enzymes are molecules, mostly proteins (except ribozyme - nucleic acid) that increase the rate of a chemical reaction and helps it to proceed faster without getting themselves consumed during the process. There are different classes and types of enzymes.

3. Apoenzyme - Some enzymes are in an inactive state and require binding of an organic or inorganic molecule to them (cofactor) to cause activation. In this case, the incomplete and inactivated part of the enzyme without cofactor is called apoenzyme.

Holoenzyme - when apoenzyme associates with its corresponding cofactor, then this complete and active structure is called holoenzyme.

4. a) Enzyme perform different functions in various processes such as digestion, cell division etc. on the basis of their type such as oxidation-reduction, ligation, group transfer, hydrolyses, isomerization, removal of groups, polymerization.

b) Enzymes can be involved in various reactions in body such as oxidation-reduction, DNA/RNA replication, cell division, release of energy, storing of energy, etc.