Feedback inhibition

Definition

Feedback inhibition is a regulatory mechanism in which the end product of a metabolic pathway inhibits an enzyme involved earlier in the pathway. This prevents the overproduction of the product and helps maintain metabolic balance.

5 Must Know Facts For Your Next Test

1. It often involves allosteric enzymes, which are regulated by molecules binding to a site other than the active site.
2. Feedback inhibition is typically reversible, allowing for dynamic regulation of enzyme activity.
3. It is crucial for conserving cellular resources and energy by halting pathways that produce excess end products.
4. An example is the inhibition of threonine deaminase by isoleucine in amino acid synthesis pathways.
5. The mechanism ensures homeostasis within microbial cells, adapting metabolism to environmental changes.

Review Questions

• What role does feedback inhibition play in microbial metabolism?
• How does an allosteric enzyme function in feedback inhibition?
• Can you provide an example of a metabolic pathway regulated by feedback inhibition?

Related terms

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

Metabolic Pathway: A series of chemical reactions occurring within a cell that lead to the conversion of one or more substrates into final products.

Homeostasis:

The ability of an organism or environment to maintain stability despite changes.