Enzyme induction and repression

BY

S.SRIVIDHYA

III BIOCHEMISTRY

What is Enzyme Induction?

A process in which a molecule (e.g. a drug) induces (i.e. initiates or enhances) the expression of an enzyme.

An enzyme inducer is a type of drug which binds to an enzyme and increases its metabolic activity.

Regulated by exposure to drugs and environmental chemicals leading to increased rates of metabolism.

Example: lac operon

Enzymes that are susceptible to induction are said to be “inducible”

enzymes kick into production when needed, remain dormant otherwise.

Enzyme induction can increase the metabolic clearance of a concomitantly administered drug, resulting in reduced efficacy, which may comprise the therapeutic effectiveness of a drug.

What is Enzyme Repression?

Effectors can associate with the operator and alter the configuration so that the binding of the polymerase occurs less efficiently or not at all. This effect is known as repression.

Example: trp operonFeedback inhibitionPrevents wasting of energy

Importance of enzyme induction

Essential to understand various reactionsthat occur inside the body

Important to analyse drug reaction

Study toxicity

Causes less or over production of hormones

Inducer molecule merges with ‘repressor’-induction

Repressor binds to ‘operator’-repression

References:

http://www.innovateus.net/health/wat-enzyme-induction

https://www.youtube.com/watch?v=qiBMpU_Xik