what are proteins? give there main sources.
Answers
Proteins are essential nutrients for the human body.They are one of the building blocks of body tissue and can also serve as a fuel source. As a fuel, proteins provide as much energy density as carbohydrates: 4 kcal (17 kJ) per gram; in contrast, lipids provide 9 kcal (37 kJ) per gram.
Proteins are polymer chains made of amino acids linked together by peptide bonds. During human digestion, proteins are broken down in the stomach to smaller polypeptide chains via hydrochloric acid and protease actions. This is crucial for the absorption of the essential amino acids that cannot be biosynthesized by the body.
Dietary sources of protein include both animals and plants: meats, dairy products, fish and eggs, as well as grains, legumes and nuts. Vegans can get enough essential amino acids by eating plant proteins.
Proteins are the substances that build the base (protoplasm) of living cells. The main sources of proteins are as follows :-
- Eggs
- Milk
- Soybean
- Pulses, etc