PROTEINS

PROTEINS ,

•      Made up of Carbon, Hydrogen, Oxygen, Nitrogen and sometimes Sulphur.

•      Important for growth and repair of the body (75% of our body is proteins only).

•      Made up of amino acids. Amino acids are of 2 types :

1.     Essential Amino Acids : They cannot be synthesised in the body and must be taken in the diet. They include isoleucine, leucine, lysine, methionine, phenylalanine, threonine, tryptophan and valine.

2.     Non-essential Amino Acids : They are synthesised in the body and do not need to be taken from outside. These include alanine, arginine, asparagine, aspartic acid, cysteine, glutamine, glutamic acid, glycine, histidine, proline, serine ana tyrosine.

•      Proteins are first broken into amino acids and then digested.

•      Some important proteins are :

□  As Enzymes : As catalyst in digestion (Eg- Pepsin, Trypsin)

As a Hormone : To regulate body functions (Eg- Insulin, Glucogon, ACTH)

In transport of different substances- (Eg- Haemoglobin-Transports 0₂ in blood, Myoglobin-Stores 0₂ in muscles)

As contractile proteins for contraction in Muscles-  (Eg- Actin and Myosin)

 Structural proteins : (Eg- Collagen-Component of connective tissue, bones, tendons, cartilage Keratin-Component of skin, feathers, nails, hair, horn)

□   Protective proteins : To fight infections (Eg- Gamma globulins)

□   Visual proteins : Rhodopsin and Iodopsin of rods and cones are proteins only. (Rods and Cones are the cells which are present in Retina of the eye).

, About 70-100 gms of proteins are daily needed.

, Sources : Groundnuts, soyabean, pulses, lean meat, fish, eggs, milk, etc.