Question

When and in what system do the phenomena of feedback repression operate in a cell system?

Answer 1

In a cell system, feedback repression operates when the end-product of a metabolic pathway (such as an amino acid like tryptophan) accumulates in excess. This phenomenon occurs within repressible operon systems, which are typically associated with anabolic (biosynthetic) pathways responsible for building complex molecules. When the concentration of the end-product becomes high enough, it acts as a co-repressor to switch off the genes, preventing the cell from overproducing a substance it already has in abundance.