One of the most important secrets of the nature is that it has created a variety of organisms. Size, shape, structure and function of each organism (including human) differ from each other. Among humans husband and wife contribute sperms and egg respectively. Sperms travel to egg through their tail and fertilises the egg.

Egg is converted into embryo which differentiates and forms all parts of body involving several steps of growth. Human body does all functions as per its requirements. Do you know? Sperm motility, fertilisation, cell division and differentiation, and all cellular works cannot be done without the involvement of proteins.

Apart from this, the fragrance which we smell, the food that we digest the beautiful flower colours and shape of animals and even human beauty which we observe, all are possible because of functions rendered by proteins.

We inhale oxygen which is transported from alveoli to blood capillaries of lungs. Oxygen is transported to all parts of body through haemoglobin (i.e. a globular blood protein).


Human body shows reflex action. Body muscles immediately contracts and then relax. The muscular protein (myoglobin) takes part in contraction and relaxation. This phenomenon was discovered about 400 years ago.

The world of protein is very diverse and peculiar. Classification of the proteins on the basis of their structure and solubility in water is given. There are several thousands of proteins found in an organism.

However, microbial proteins are different from the plants, and those of plants are different from animals and humans. For a long time scientists have been making attempt to understand such diverse functions of the protein.

Proteins occupy a central position in giving shape and functioning of living organisms. All phases of chemical and physical activities of a cell are linked with proteins.


All works which the organisms (including humans) and the cells of organisms do are possible because of enzyme/proteins found in cells and tissues for example metabolism, locomotion, movement, flower colour, body texture, shape, size, smell, body response, fertilisation, cell division and development, etc.