Proteins are very important chemical compounds contained by all plants and animals. Probably life would not exist without proteins.
The word ‘protein’ originated from a Greek word which means ‘first’, because proteins are considered to be the most essential part of the living matter. These chemical compounds are made up of chains of amino acids. There are more than 21 amino acids. Each amino acid has carbon, nitrogen, oxygen and hydrogen as its constituents. The different amino acids combine in different ways to form thousands of proteins.
Proteins work in many different ways in the body. An important group of proteins, called enzymes act as catalysts in many biochemical reactions. Enzymes are essential for metabolic activity of the body. Some hormones, such as insulin, are also proteins. They are called regulatory proteins because they regulate blood pressure and blood glucose level. Immune proteins protect the body against infection. Transport proteins such as haemoglobin carry vital substances to different parts of the body. Movement of the muscles is helped by proteins called contractive proteins. Thus proteins are vital for the body.
Proteins are made of amino acids. Each amino acid has carbon, nitrogen, oxygen and hydrogen in it; some also have small amounts of other elements. Plants make their own amino acids, and can therefore make their own proteins. Animals make some amino acids, but not all that are necessary for life. These amino acids which animals cannot make them are called essential amino acids. Animals get them from their food. When an animal eats protein-rich food, the proteins are broken down into individual amino acids. These amino acids are then used by the body to make different proteins, through a process known as protein synthesis.
Protein-rich food is necessary for the well being of an organism. Foods such as milk, eggs, fish, meat and cheese have sufficient proteins, as well as the essential amino acids. Some substances such as rice and potato, do not have certain essential amino acids, and are not considered as good protein sources.
A deficiency of proteins makes a person slow, listless and highly susceptible to infectious diseases. Protein deficiency may also cause brain damage and mental retardation. Hence one is advised to take a balanced diet, rich in proteins.