Technically speaking,proteins are any of a group of complex organic macromolecules that contain carbon, hydrogen, oxygen, nitrogen, and usually sulfur and are composed of one or more chains of amino acids.
But for better understanding we can say that proteins are complex substances that are made up of thousands of smaller substances called amino acids,i.e amino acids are the building blocks for proteins.
Along with carbohydrates and fats, proteins are called macro nutrient as they are needed in large quantities by the body. But unlike carbohydrates and fats, the body cannot store protein and has to be supplied through the diet.
There are 20 different amino acids. They are linked together to form peptides which are small chains of amino acids, which in turn link together to form large proteins
These amino acids can be classified into two groups
Non essential amino acids and
Essential amino acids
Non essential amino acids are not to be mistaken for those that are not required by the body. It means that the body can synthesize these amino acids and there is no need to be supplied by the diet. They are 11 in number and the body can make them with the chemicals that are already present in the body.
These include:
• Alanine
• Arginine
• Asparagine
• Aspartic Acid
• Cysteine
• Glutamic Acid
• Glutamine
• Glycine
• Proline
• Serine
• Tyrosine
Essential amino acids are 9 in number and they have to be supplied by the food stuffs from the diet.
• Histidine
• Isoleucine
• Leucine
• Lysine
• Methionine
• Phenylalanine
• Threonine
• Tryptophan
• Valine
Of these arginine, cysteine, glycine, and tyrosine are sometimes referred to as ‘Conditionally essential’. Though they are synthesized by the body, sometimes due to genetic abnormalities, the body is not able to produce them and hence have to be supplied through the diet.
Animal protein called ‘complete proteins’ as they contain all the 9 essential amino acids. Plant proteins on the other hand plant proteins are termed as ‘incomplete proteins’ as they have at least one amino acid missing. There is an exception to this – Soy protein. It has all the essential amino acids.
But vegetarians need not worry for by combining one or more plant protein we can plan the diet all amino acids. Grains and pulse combination is an excellent way to obtain all the amino acids. I feel the Indian cuisine has a lot of option that has been followed for a very long time. Like arisi parippu sadham,dhal-chawal etc.,combining rice with sambar[which has toor dhal/pigeon pea],Idli,Dosa,Chapathi with Dhal etc.
Almost everyday there is a combination of cereal with at least one kind of legumes.These are just a few examples and there are similar options in other cuisines too.
Vegans are not to be disheartened. A vegan diet with legumes, nuts, seeds and whole grain can take care of the amino acid needs. As said earlier soy protein is a complete protein and hence all form of soy protein can be included.
But in the modern days when pizzas and burgers rule the world, we can go in for healthier options like peanut butter spread for toast instead of jam/butter, mixing legumes with noodles/pasta, etc. Just make sure that you have a cereal and a pulse in a day and the body will take care of the rest.
very informative. nice post on proteins.
Dear Padmajha
This is an wonderful and timely and proper scientific article. These days I am so tired of seeing useless articles giving totally wrong picture of the whole diet system in the name of health food. ( some are very scientific no doubt). This article will be very helpful for all.
will be looking forward to the next eagerly.
Have a nice weekend