KCAT KM Meaning

Hello sir I want to know about the Kcat and Km ¬so please provide me information about the meaning of these terms.

[Shaleen]

kcat,kd and Km are terms used in structural Biochemistry in the description of an enzyme which follows the Michaelis-Menten kinetics.

KCat Term

Kcat is a constant that describes the turnover rate of an enzyme-substrate complex to product and enzyme.

It is also the rate of catalyst with a particular substrate.

KM

KM is the Michaelis constant that describes the amount of substrate needed for the enzyme to obtain half of its maximum rate of reaction

It is an important constant to study the ability of catalysis reaction of enzyme with specific substrate.

Kd

It is dissociation constant which describe how affinity two reactants are in a reaction.

About the Michaelis constant

KCAT/KM measures catalytic efficiency.

This measure of efficiency is used to determine the rate is limited by the creation of product or the amount of substrate in the environment.

If the rate of efficiency is:

1. HIGH, KCAT is much larger than KM, and the enzyme complex converts a greater proportion of the substrate it binds into product.

2. LOW, KCAT is much smaller than KM, and the complex converts a lesser proportion of the substrate it binds into product.

kcat/KM measures the catalytic efficiency, though, only when the substrate concentration is much lower than the KM.