Feedback inhibition

Definition

Feedback inhibition is a regulatory mechanism where the end product of a metabolic pathway inhibits an enzyme involved in the pathway, preventing overproduction. This helps maintain homeostasis within the cell.

5 Must Know Facts For Your Next Test

1. Feedback inhibition typically targets the first enzyme in a metabolic pathway to prevent wasteful accumulation of intermediates.
2. It ensures that cells do not expend energy unnecessarily by halting production when sufficient end product is available.
3. This mechanism is crucial for regulating pathways such as glycolysis and the citric acid cycle.
4. Allosteric enzymes are often involved in feedback inhibition; they change shape upon binding with an inhibitor molecule.
5. Feedback inhibition can be reversible, allowing pathways to resume function when end product levels decrease.

Review Questions

• What role does feedback inhibition play in cellular metabolism?
• How does feedback inhibition help maintain cellular homeostasis?
• Which type of enzyme is commonly involved in feedback inhibition?

Related terms

Allosteric Enzyme: An enzyme whose activity is modified by the binding of a regulatory molecule at a site other than the active site.

Metabolic Pathway: A series of chemical reactions within a cell, facilitated by enzymes, leading to the biosynthesis or breakdown of substances.

Homeostasis:

The state of steady internal conditions maintained by living systems despite external changes.