FSc Notes Biology Part 1 Chapter 3 Enzymes Definitions

Activation energy:
The minimum amount of energy required to start a reaction is called activation energy.

Activators:
The detachable co-factors are called activators.

Active site of enzyme:
The site where substrate attaches is called active site of enzyme.

Apoenzyme:
An enzyme, with co-enzyme or prosthetic group removed is called apoenzyme, it is inactive form.

Co-enzyme:
The loosely attached non-protein part with an enzyme is called co-enzyme.

Co-factors:
Some enzyme contain a non-protein part called co-factor.

Enzyme:
The biological active protein which speed up chemical reactions in the cell are called enzyme.

Enzyme inhibitors:
A chemical substance which can react in place of substrate with the enzyme but is not transferred into products and block the active site of the enzyme temporarily or permanently is called inhibitor.

Holoenzyme:
An activated enzyme, consisting of polypeptide chain and co-factor is called holoenzyme.

Lock and key model:
According to this model, one specific key can open only a specific lock. Similarly, a specific enzyme can transform only specific substrate into products.

Optimum pH:
An optimum pH is a marrow range of pH in which enzyme function effectively.

Optimum temperature:
The specific temperature at which an enzyme can work at maximum rate is called optimum temperature.

pH:
The anti-log or negative log of the hydrogen ion concentration is called pH always greater than 7.

Prosthetic group:
The covalently bonded non-protein part is called prosthetic group.