Amino acids and trace elements are indispensable to human bodies. Among them, the human body requires 22 kinds of amino acids, which are divided into non-essential amino acids and essential amino acids (which cannot be synthesizes by the body itself). Below we give a detailed analysis of 18 amino acids.

It is known that there are twenty varieties of basic amino acids, among which lysine, threonine, leucine, isoleucine, valine, methionine, tryptophan and phenylalanine cannot be manufactured by the human body. We call it essential amino acids and need to be provided by food. In addition, the human body's ability to synthesize arginine and histidine is insufficient to meet its own needs, and they needs to be taken partially from the food, which we call semi-essential amino acids. The remaining ten amino acids can be made by the human body, which we call non-essential amino acids.

Amino acids are the basic building blocks of proteins, there are more than 200 kinds, among which 20 of them play an important role in animal nutrition and are widely recognized. We call them standard amino acids. According to the nutritional needs of animals, they are usually divided into two major categories: essential amino acids and non-essential amino acids. In the standard amino acids, the animal body cannot synthesize itself, or the speed or quantity of synthesis cannot meet the normal growth of the animal, which can be provided by feed. Non-essential amino acids does not mean non-necessary, but rather a class of amino acids that the animal can synthesize itself or require less. Among the essential amino acids, the most replenished amount in the feed is called the first limiting amino acid, and the supplementary amount is called the second limiting amino acid.

Amino acid is one of the many biologically active macromolecules that construct biological organisms, and is the basic material for constructing cells and repairing tissues. Amino acids are used by the human body to make antibody proteins to fight against bacterial and viral infections, to produce hemoglobin to deliver oxygen, to make enzymes and hormones to maintain and regulate metabolism; amino acids are the main substance in the production of sperm cells, and are indispensable premise substances for the synthesis of neural mediators; amino acids can provide energy for the body and brain activities, and amino acids are the key to all life.

The role of amino acids in the human body:

Glycine (GLY)
 (1). Reduce blood cholesterol levels, prevent high blood pressure

 (2). Reduce blood sugar levels, prevent diabetes

 (3). Prevent blood clots

 (4). Improve muscle vitality and prevent hyperacidity

 (5). Its sweetness is 0.8 times that of sugar, which has beneficial effects on the human body

Leucine(LEU)
(1). Reduce blood sugar levels, have a role in the treatment of dizziness

(2). Promote healing of skin, wounds and bones

(3). If short of LEU, body will stop growing and lose weight.

Methionine (MET)
(1). Involved in the synthesis of choline, with the function of delipidation, prevention of arteriosclerosis and hyperlipidemia

(2). Improve muscle vitality

(3). Promote the synthesis of skin proteins and insulin

Tyrosine(TYR)
(1). Essential amino acids for adrenal hormone, thyroid hormone and melanin

(2). Prevent Alzheimer's disease

(3). Promote metabolism, increase appetite

(4). Have a role in the treatment of chronic diseases, such as gastric ulcer, neurological inflammation and dysplasia

(5). Related to pigmentation

Histidine (HIS)
(1). Participate in blood globulin synthesis and promote blood production

(2). Produce histamine, promote vasodilation, increase the permeability of the blood vessel wall

(3). Have special effects for healing stomach, duodenum and other

(4). Promote gland secretion, have an effect on allergic diseases

(5). Can treat peptic ulcer, dysplasia and other symptoms

(6). Have role for the treatment of cardiac insufficiency, angina pectoris, lowering blood pressure, asthma and rheumatoid arthritis

Threonine(THR)
It is necessary for human body, when lacking, it will make people lose weight and even die.

Alaine (ALA)
(1). It can promote the metabolism (decomposition) of alcohol in the blood to enhance liver function, and protect liver.

(2). The sweetness is 1.2 times that of sugar

To be continued in Part II…

Reference

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Proline is an exception to this general formula. It lacks the NH2 group because of the cyclization of the side chain and is known as an imino acid; it falls under the category of special structured amino acids.
Blaser HU (1992). "The chiral pool as a source of enantioselective catalysts and auxiliaries". Chemical Reviews. 92 (5): 935–52. doi:10.1021/cr00013a009.
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