Feedback Inhibition Essay

UNIVERSITY OF MUMBAI
DEPARTMENT OF LIFE SCIENCES

Feedback Inhibition
Feedback inhibition is a reaction product is used to regulate its own further production. Cells have evolved to use feedback inhibition to regulate enzyme activity in metabolism, by using the products of the enzymatic reactions to inhibit further enzyme activity. Metabolic reactions, such as anabolic and catabolic processes, must proceed according to the demands of the cell. In order to maintain chemical equilibrium and meet the needs of the cell, some metabolic products inhibit the enzymes in the chemical pathway while some reactants activate them.

Metabolic pathways are a series of reactions catalysed by multiple enzymes. Feedback inhibition, where the end product of the pathway inhibits an earlier step, is an

Feedback inhibition balances production of amino acids. For eg, the enzyme threonine deaminase is inhibited by one of its products, the amino acid isoleucine. If the reaction weren't shut off, the enzyme couldn't synthesize other amino acids that the cell requires. However, the reaction restarts when there is low isoleucine. To accomplish this, the enzyme binds to another amino acid valine, which turns the enzyme back on.
Avoiding Energy Depletion
Feedback inhibition is also necessary to prevent enzymes from breaking down too many molecules that are energy sources for the cell, such as glucose. Inhibition takes place in glycolysis, the process of breaking down the sugar glucose to produce the cells “energy currency" molecule ATP. ATP slows down the enzymes until they are structurally modified and stop catalyzing reactions. The enzymes are inhibited when blood glucose levels are low, so that there isn't a total depletion and the cell then has a chance to accumulate more glucose for later use.
When Feedback Inhibition