Protein– Proteins are highly complex organic compounds, which are made up of carbon, hydrogen, oxygen, and nitrogen. Some of the proteins also contain several elements, such as sulphur and phosphorus. Proteins are very important in our food for the growth and repair of the body. Proteins are essential for the growth of the children and teenagers, which are needed for maintenance and making good the wear and tear of body tissues in adults.

Proteins are also called as the building blocks of life because they are essential to grow new tissues, repair danage and maintain the overall structure of muscles, organs, and body. Proteins are also made up of nitrogen, which contains compound called amino acids. There are more than 20 of these amino acids and they all occur in almost all proteins.

We can get proteins from plant sources as well as animal sources. Some of the best sources of plant proteins are beans, ground nuts, and whole cereals including wheat, maize, and pulses. There are also some animal proteins are eggs, lean meat (meat without fat), milk, and cheese. The most valuable proteins are found in milk, meat, and eggs. They contain all the amino acids required by our body. These proteins are particularly needed by children.

Important functions of proteins – The functions or properties of food proteins may depends on the amino acids of which they are made. There are some important types of proteins required by our body such as hormones proteins, protective proteins, enzymes proteins, structural proteins, transport proteins, and contractile proteins.

The functions of these proteins are

1. The function of hormone proteins is to regulate the various body functions. Insulin is also a hormone protein.
2. The function of protective protein is to help fight infection in our body. Ganna globulins are present in the blood, which is an example of protective proteins.
3. The function of enzyme protein is to catalyze the biochemical reactions like digestion. Pepsin and Trypsin are enzyme proteins.
4. The function of structural protein is to form the structural elements of the cells and tissues of our body. Collagen is an example of structural protein.
5. The function of transport protein is to carry different substances from the blood to the various tissues of the body. Haemoglobin is an example of transport protein.
6. The function of contractile protein is to help in the contraction of muscles and other cells of our body. Myosin and Actin are contractile proteins.