What is meant by enzyme specificity?

Enzyme specificity means that each enzyme works only with a particular substrate or a specific type of reaction.

This happens because the active site of an enzyme has a unique shape that matches only certain substrates — like a key fitting into one specific lock.

Types of enzyme specificity (simple):

1. Absolute specificity:
   The enzyme acts on only one substrate.
   Example: Urease works only on urea.
2. Group specificity:
   The enzyme acts on a group of similar substrates.
   Example: Hexokinase acts on several sugars like glucose and fructose.
3. Linkage specificity:
   The enzyme acts on a specific type of chemical bond.
   Example: Lipase breaks ester bonds in fats.
4. Stereochemical specificity:
   The enzyme acts on one specific form (shape) of a molecule.
   Example: Some enzymes act only on the D-form of sugars.

In short:
Enzyme specificity means an enzyme is selective — it works only with the right substrate because their shapes fit perfectly together.