Final answer:
Catabolite repression is a regulatory mechanism in cells that controls the expression of certain genes involved in catabolic pathways.
Step-by-step explanation:
Catabolite repression is a regulatory mechanism in cells that controls the expression of certain genes involved in catabolic pathways. It occurs when the cell senses the presence of a preferred energy source, such as glucose, and represses the expression of genes involved in the breakdown of other substrates. This regulation is achieved through the binding of a protein called catabolite activator protein (CAP) to the promoter regions of target genes.