Question

discuss the composition and structure of enzymes and discuss the factors that modify enzyme structure and function

Answer 1

All known enzymes are proteins. They are high molecular weight compounds made up principally of chains of amino acids linked together by peptide bonds.

Many enzymes require the presence of other compounds - cofactors - before their catalytic activity can be exerted. This entire active complex is referred to as the holoenzyme; i.e., apoenzyme (protein portion) plus the cofactor (coenzyme, prosthetic group or metal-ion-activator) is called the holoenzyme.

Following are the factors that affect the enzyme structure and activities:
1. Substrate concentration:
The activity of an enzyme also increases with the increase in substrate concentration. If the substrate concentration increases, then the availability of the active site would decrease. This will affect the activity of an enzyme and limit the reaction rate.
2. pH
Each enzyme has its optimal pH in which they work. For example pepsin and trypsin work on acidic pH. The enzymes are globular proteinaceous structure, form by the interaction of the hydrogen bond between the side chains of the protein. Any change in the cause deionization of side chain which results in the denaturation of the enzyme.
3. Temperature:
Each enzyme works on its optimal temperature. Any alteration in temperature affects the activity of an enzyme, and it also leads to denaturation of an enzyme.
4. Enzyme cofactor and coenzyme:
Each enzyme requires cofactors (inorganic ion or protein organic molecules) for their work. The non-availability of these cofactors decreases the activity of an enzyme.
5. Enzyme inhibitors:
The inhibitors of an enzyme bind to the active site which affects the activity of an enzyme.