What is the Difference Between Feedback Inhibition and Feedback Repression?

Feedback inhibition and feedback repression are two ways of enzyme inhibition that help control the production of certain compounds in biochemical pathways. The main differences between them are:

1. Feedback Inhibition:

• Involves the end product itself inhibiting the enzyme that catalyzes the first reaction in the biochemical pathway.
• The end product binds to the active site of the enzyme, preventing the binding of the substrate.
• Typically acts at the first committed step of the pathway, meaning the first step that's effectively irreversible.
• Regulation is done at the first step, no matter how many steps are found in the multi-step pathway.

1. Feedback Repression:

• Involves the end product or its derivatives inhibiting the production of the enzyme at the gene level.
• The end product or its derivatives repress the synthesis of the enzyme, affecting the enzyme's production.
• Regulation can happen at any step where there is a regulatory enzyme or the step which we call regulation will happen at that step and its synthesis.

In summary, feedback inhibition focuses on the end product directly inhibiting the enzyme catalyzing the first reaction in a biochemical pathway, while feedback repression involves the end product or its derivatives inhibiting the production of the enzyme at the gene level. Both mechanisms help control the production of certain compounds in biochemical pathways, but they act at different levels of the process.

Comparative Table: Feedback Inhibition vs Feedback Repression

Feedback inhibition and feedback repression are both mechanisms used to regulate the production of end products in biochemical pathways. Here is a table highlighting the differences between the two:

In feedback inhibition, the final product inhibits the first enzyme in the pathway, known as the allosteric enzyme, which catalyzes the first reaction. This inhibition occurs by binding with the active site of the enzyme, preventing the binding of the substrate with the enzyme, and ultimately controlling the amount of end product.

In feedback repression, the end product inhibits the production of the enzyme at the gene level, effectively controlling the amount of end product through enzyme synthesis inhibition. Feedback repression can occur at any step in the pathway with a regulatory enzyme, and its regulation is slower and less precise compared to feedback inhibition.