Without protein our body cannot function properly.
Our body nerves, tissues, bones all are made up of proteins. So proteins become very necessary for them to grow and repair. It also used to produce some hormones and enzymes in our body .proteins are made up of amino acids. Our body produces non essential amino acids and also requires the essential amino acids which we take from the food. Amino acids are present in the proteins.
It has been proved by the physicists that nearly 98% of our body atoms get replaced in a year. After every six months liver replaces its cells and stomach lining in five days. We get entirely new skeleton in three weeks. And also old blood cells are replaced by new one. So for all this purpose of growth and repairing proteins are essentially required in our body. Almost every cell present in our body is replaced after a particular time period. So from now be careful about your diet if you are not. When you eat, food breaks the proteins present into amino acids which are again re-assembled to regulate all the above mentioned functions.
Another function of protein is that it produces antibodies which fight with the bacteria, viruses, toxins and many foreign substances that are harmful for the body. Moreover when you are injected by cold, flu etc. it helps in the cellular healing process.
Mostly people think that the animal meat is a good source of proteins no doubt it is but milk, cheese, eggs, are also rich in proteins. Plant proteins are not complete proteins such as grains, cereals etc. so it is required to have more complete source of protein. Some of the protein is also used with these foods that are stored earlier in our body.