Question

In bacteria, glucose is utilised first, even if other sources of sugar are available. This happens through a mechanism known as

(a) catabolite repression

(b) enzyme repression

(c) operon repression

(d) positive feedback mechanisms

Answer 1

Answer is : (a) catabolite repression

Catabolic repression is a system of gene control in some bacterial operons in which glucose is used preferentially and the metabolism of other sugars is repressed in the presence of glucose.

Catabolite repression allows microorganisms to adapt quickly to preferred carbon/energy source (like glucose) first. This is achieved through inhibition of synthesis of enzymes involved in catabolism of carbon sources.