Proteins are essential macronutrients for the human body. They are one of the building blocks of body tissue and can also serve as an energy source . Proteins are polymer chains made of amino acids linked together by peptide bonds .
Beside classifying of protein on the basis of soluble and insoluble proteins have been further classified based on the following –
- Classification Based On Chemical Nature.
- Classification Based On Chemical Properties.
- Classification Based On Amino Acid Composition.
Classification of protein based on Amino Acid Composition
Amino Acids are organic compounds which combine to form proteins. Hence they are referred to as the building components of the proteins. Nutritionally, amino acids are classified on the basis of the body ability to synthesize them.
- Essential Amino Acid ( Indispensable and not synthesized in the body )
- Non-Essential Amino Acid ( Dispensable and can be synthesized in the body )
Indispensable Amino Acid must be a part of the diet while dispensable amino acids need not to be present in the food. There is a third group of amino acids which are conditionally essential and characterized by two features. Firstly their synthesis uses other amino acid precursors and confined to specific organs.
There are a total 10 Essential, 5 Non-Essential and 3 conditionally amino acids available.
|Essential Amino Acids||Non-Essential Amino Acids||Conditionally Amino Acids|
|1. Glutamine Acids|
2. Alanine Proline
3. Aspartic Acids
Based on the amino acids composition proteins are therefore classified as-
- Complete Proteins
- Incomplete Protein
- Partially Complete Protein
A complete protein contains all nine essential amino acids ( I.e Egg ,Checken ). These are essential because they can not be synthesized in the human body. They need to be in your diet. A lot of plant proteins are not under complete protein but it can be combined to provide all necessary amino acids and even eating a different plant protein later in the day should be sufficient to meet your protein needs. Some complete protein sources are egg, Meat.
Incomplete Proteins are missing or do not have enough amino acids making the protein complete . Most of the plant protein such as beans, peas , grains , nuts and vegetables are incomplete protein sources .
Partially Complete Proteins
Partial complete Proteins is a protein in take that does not incorporate all essential amino acids however a limited quantity of 1 or extra of them. Example – Wheat protein , These proteins promote moderate growth and partially lack one or more essential amino acids.