Updated By: LatestGKGS Desk
Biology: Enzymes, definition, their chemical and physical properties
Definition of an Enzyme (Bio-Catalyst)
An enzyme is a biological catalyst that tremendously accelerates the rate and efficiency of chemical reactions in living organisms. During such reactions, an enzyme acts upon substrates and converts them into different molecules referred to as products. Nearly all cellular metabolic processes require an enzyme to occur at a rate rapid enough to sustain life. An enzyme is a protein, but not all proteins are enzymes.
The important properties of enzymes are as follows:
(i) The enzymes are generally proteins which are high molecular weight complex globular proteins. They can associate with a non-protein substance for their activity.
(ii) The enzymes do not start a chemical reaction but only accelerate it. They combine temporarily with the substrate molecules and are not consumed or changed permanently in the reaction which they catalyze.
(iii) The enzyme controlled reactions are reversible.
(iv) The enzymes are specific in action. An enzyme catalyzes only a particular kind of reaction or acts on a particular substrate only.
(v) The enzymes are thermolabile i.e., heat sensitive and can function best at an optimum temperature. Similarly, enzymes show maximum activity at optimum pH.
(vi) The enzymes are inactivated by poisons and radiation.
