biological role of protein and importance of protein
Answers
Hair and nails are mostly made of protein. Your body uses protein to build and repair tissues
Answer:
★ Proteins:
Proteins are the long chain polymers of amino acids and possess high molecular weight. They contain C, H, O and N. The presence of N distinguishes them from carbohydrates and lipids. Some proteins contain sulphur, while few proteins contain phosphorus also. Cells contain a large number of proteins.
★ Biological functions of proteins:
The biological importance of proteins is as follows:
i. Membrane proteins: Cell membrane consists of proteins and lipids. All membrane bound cell organelles have lipids and proteins in their membranes.
ii. Enzymes: All enzymes are proteins. Enzymes may contain some other non-protein part also along with protein. e.g. Amylase.
iii. Hormones: Hormones are proteins. They play an important role in the regulation of metabolic reactions in the body, e.g. Insulin, thyroxine.
iv. Transport protein: Haemoglobin which is present in R.B.C. of man is a type of protein. It is useful for transportation of oxygen.
v. Contractile protein: Muscle fibres consist of proteins, which help in contraction. e.g. Myosin.
iv. Structural protein: These proteins form parts of cells or tissues. e.g. Keratin is present in hair and skin, while elastin is present in connective tissue.
vii. Defensive proteins: Useful for the protection of body. e.g. Immunoglobin, thrombin for clotting of blood.