Question

Why do enzymes act on very specific substrates?

Short answer

Enzymes are made up of a biomolecule named proteins, which have specific shapes. These shapes are the consequence of specific amino acid sequences.

The specific active site present in every enzyme is the groove where the substrate can bind. The site's shape is complementary to the substrate's shape to fit within the groove perfectly. This attribute of enzymes confers specificity for their specific substrate binding.

Step-by-step solution

Enzymes

Enzymes are those proteins that are accountable for increasing the rate of the enzyme. They are not consumed while speeding up the reaction. It helps in lowering the activation energy barrier. Thus the reactants can change into the transition state early and thus speed up the reaction.

Substrate

The substrates are those chemical compounds involved in a reaction as reactants, and enzymes act on them to speed the reaction.

This compound can bind with the enzyme to form a complex together. It is called the enzyme-substrate complex. Further, the enzyme acts on the compound and causes the conversion of the reactant into the product.

Specificity of an enzyme for a substrate

The specificity of the enzyme is conferred by the shape obtained due to the specific amino acid sequence as it is a protein.

The active site is the specific place of the enzyme where the reactant can bind to the enzyme.It comprises a few amino acids, while the rest of the amino acid sequences of the enzyme protein contribute tothe framework for its shape.

The enzyme's shape where the substrate binds is accountable for its specificity as the shape is only complementary to the shape of the substrate. The substrate can easily fit within site, and the enzyme can continue the further catalytic function.