1. Proteins are structural components of cells and tissues eg. Keratin forms hairs.
2. Blood protein haemoglobin transports oxygen while muscles protein myoglobin transports oxygen to muscles.
3. Blood protein thrombin helps in coagulation of blood.
4. Proteins in the form if hormones play important role eg. growth hormones and insulin
6. Chemical reaction require enzymes and enzymes are made up of Protein.