Feedback Inhibition

Introduction

• Feedback inhibition is a regulatory mechanism used by cells to control metabolic pathways.
• It involves the inhibition of an enzyme at the beginning of a metabolic pathway by the end product of that pathway.

Mechanism of Feedback Inhibition

• In feedback inhibition, the end product of a metabolic pathway acts as an inhibitor.
• The end product binds to the enzyme responsible for the first step in the pathway, typically at the enzyme's allosteric site (a regulatory site distinct from the active site).

Effect on Metabolic Pathway

• When the end product binds to the enzyme, it causes a conformational change in the enzyme's shape.
• This change inhibits the enzyme's activity, preventing it from catalysing the conversion of substrate to product in the metabolic pathway.
• As a result, the entire metabolic pathway is temporarily halted.

Control of Metabolism

• Feedback inhibition is a crucial mechanism for controlling metabolic pathways.
• It ensures that the production of end products is regulated and does not exceed the cell's immediate needs.
• When the concentration of the end product decreases, the inhibition is relieved, and the metabolic pathway can resume.

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Biology

Feedback Inhibition

Summary

• Feedback inhibition is a regulatory mechanism where the end product of a metabolic pathway inhibits the enzyme responsible for the pathway's first step.
• This inhibition stops the metabolic pathway when the concentration of the end product is sufficient, preventing overproduction.
• When the end product concentration decreases, the pathway resumes.