The word protein is derived from the Greek word ‘proteos’ meaning first. The name indicates that they are very essential for the growth and maintenance of the body. They occur in the protoplasm of the living cells. Proteins fulfill a wide range of functions such as mechanical movements, transporting cellular necessities such as oxygen, metal etc.
Fibrous Proteins (Examples: Silk, Skin, wool etc)
1. They are insoluble in water, acids, bases etc.
2. They have comparatively stronger intermolecular forces of attraction.
3. They have thread like structure.
4. They have helical or sheet structure.
Globular Proteins (Examples: Egg albumin, casein of milk)
1. They are soluble in water, acids, bases etc.
2. They have weak intermolecular hydrogen bonding.
3. They have folded, ball like structure.
4. They have three dimensional shape.