1, the digestion and absorption of protein in the body through the amino acid to complete: as the body of the first nutritional elements of the protein, its role in food nutrition is obvious, but it can not be directly used in the human body, and Is used by becoming a small molecule of amino acids.
2, nitrogen balance effect: When the daily diet of protein and the amount of appropriate, the intake of nitrogen from the feces, urine and skin emissions of nitrogen equal, known as the total balance of nitrogen. Is actually the protein and amino acids between the continuous synthesis and decomposition of the balance between. Normal daily intake of protein should be kept within a certain range, suddenly increase or decrease the amount of food intake, the body can still regulate the metabolism of protein to maintain nitrogen balance. Eating too much protein, beyond the body to adjust the ability to balance the mechanism will be destroyed. Do not eat protein, the body protein is still decomposition, continued negative nitrogen balance, if not timely to take measures to correct, will eventually lead to antibody death.
3, into sugar or fat: amino acid catabolism produced by a-keto acid, with different characteristics, sugar or lipid metabolism pathway for metabolism. a-keto acid can be synthesized into new amino acids, or converted into sugar or fat, or into the tricarboxylic acid to oxidize into CO2 and H2O, and release energy.
4, involved in the composition of enzymes, hormones, some vitamins: the chemical nature of the enzyme is a protein (amino acid molecules), such as amylase, pepsin, cholinesterase, carbonic anhydrase, transaminase and so on. The composition of the nitrogen-containing hormone is a protein or a derivative thereof, such as growth hormone, thyroid stimulating hormone, adrenaline, insulin, promoting intestinal hormone and the like. Some vitamins are converted by amino acids or in combination with proteins. Enzymes, hormones, vitamins in the regulation of physiological function, catalytic metabolism plays a very important role.
5, the body needs of essential amino acids: adult essential amino acid requirements of about 20% of protein requirements, - 37%.