Question

What are enzymes? Give 3 examples of it.

Answer 1

Hint:There are a lot of metabolic reactions occurring in the living organisms that need to be operated at a fast rate. Enzymes play a key role in such metabolic reactions as biocatalysts.

Complete answer:
Enzymes are called biocatalysts and are proteinaceous substances that are capable of catalyzing chemical reactions of biological systems without themselves undergoing any change. The three examples of enzymes are:
Lactase – it acts on lactose and hydrolyses the lactose molecule into glucose and galactose.
Trypsin – it acts on proteins and breaks them to peptones and peptides.
Restriction endonuclease – this enzyme is used in genetic engineering for breaking DNA at specific sites.
Catalysis is the phenomenon by which the presence of a small amount of a substance enhances or reduces the rate of a reaction without the catalyst being used up or changed at the end of the reaction. Enzymes also work similarly and they are more specific than normal chemical catalysts because they have active sites that are some specific regions formed by coming together of R-groups of amino acids. The active site has a depression in the form of a crevice or pit wherein the substrate molecule fits in for undergoing change. An enzyme may also have some areas that control the conformation of active sites. These are called allosteric sites and such enzyme is called an allosteric enzyme.

Note: Enzymes neither start a chemical reaction nor make changes in the equilibrium of the reaction; they just enhance the rate of reaction and for enhancing the rate, enzymes lower the activation energy of the reaction. Also, enzymes are not imported; every cell produces its own enzymes whenever needed.