valine The great majority of proteins of our body contains all the (essential as well as non-essential) amino acids Therefore

tryptophan. valine The great majority of proteins of our body contains all the (essential as well as non-essential) amino acids Therefore our food proteins should be such that they supply all the essential amino acids In addition to the non essential aminoacid (non-essential amino acids. however, can be synthesized in our body, provided the raw materials for synthese are available). Proteins That contain all the essential amino acids (in addition to the non essential amino acids) are called first class proteins Proteins in which one or more essential amino acids are missing are called second class proteins. as a rule, the animal proteins. [That is protiens of animal origin (like the proteins Of meal, fish, milk and egg) are first class proteins One exception is. gelatin, which although an animal protein (obtaned from tendons and ligaments) is a second class protein Some vegetable proteins (that is proteins of plant origin) are second class protiens however, some vegetable proteins, e .g. rice protein. Is first class protien Previously, (unfortunately) first class proteins and second class proteins were equated witn animal and vegetable proteins respectively as it is now well known that many vegetable proteins are first class proteins, such equators are not made now Supplementary proteins An example will help. Wheat contains two proteins, gliadin and gluterin (table7.1.1.) Now, gliadin Is poor in lysine and so it is an incomplete or second class protein.Glutenin, which is also present in the wheat, is very rich in lysine. When one eate. he eats not gliadin or glutenin in scaled way cut eats wheat as a whole. so that the deficiency of giradin is made good by gluterinThis is an example of supplementary role of proteins in the world of vegetarians (Vegaris}, this knowledge seems to be naturaly present, although those vegans may be totally unaware of any idea of proteins, let alone supplementary role of proteins. Dal is an excellent source of protein in India and is always taken with roti (wheat), so that the combination of dal and roti (bread) gives a protein of good quality in the body, by virtue of their supplementary actons To add to the picture, in uttar Pradesh of India, a common practice is to take rice and rot (bread) together with dal In all principal meals. In Rajasthan of India, poor men often take 'mtshi rob' (mishi = mixed, the rotis prepared from a mixture of cereats lite bazra and wheat) In north India, one often rahes a mixture of dals (e.g. chana and urat ki dal) Vegetable curries in India are are most always made from a number of vegetables in all such examples, one thing stands common, and That s. an individual protein may be incomplete, but when several proteins are mixed up together, the result of the mixture is excellent Finally In such dishes of mixed vegetable protens. a smalt amount of milk protein (in the form of curds, s natiral item in the menu, in the world of Indian vegans) makes the cocktal still better The above discussion is inportant to remember because in India most people are poor and they cannot afford to buy animal proteins Secondary in India there are more than 150 million vegans, who out of respect for the sanctity of life do not kill animals for food (most of them however take milk although many of them are too poor To buy milk Biological value of proteins amino acid composition of our body protein may simulate closely or differ widely from the amino acid compostion of the food proteins Where the similarity is close, the food proteins (provided they have been digested satisfactory can synthesize body proteins land ibus help in replenishment of wear and tear, growth etc] more economically Such food proteins (whose amino acid con-position resembles That of our body proteins closely)