Glycine is a non-essential amino acid that has many important physiological functions in the human body. Here is a description of glycine and some common uses:

Description: 

•Chemical properties: Glycine is one of the simplest amino acids and is a building block of proteins. It is a colorless crystalline powder that is soluble in water.

•Source: Glycine can be consumed through the diet and is mainly found in protein-rich foods such as meat, fish, dairy products, and legumes.

Purpose: 

1. Protein synthesis: Glycine is an important part of protein synthesis. It is involved in the synthesis of peptides and proteins and is essential for maintaining the body's protein balance and tissue repair.

2. Neurotransmitter and nervous system function: Glycine plays an important role in the central nervous system. It can be used as a precursor substance of neurotransmitters, involved in nerve signal transmission and regulation of nervous system function, and is essential for maintaining normal nervous system activities.

3. Bile acid synthesis: Glycine is an important part of the synthesis of bile acids. Bile acids are key substances in the digestion of fat and contribute to the process of fat absorption and digestion.

4. Muscle growth and repair: Glycine plays an important role in muscle growth and repair. It can promote protein synthesis, increase muscle mass and the volume of muscle fibers, which is beneficial for athletic performance and muscle recovery.

5. Antioxidant effect: Glycine has a certain antioxidant effect, which can clear free radicals in the body and reduce the damage of oxidative stress on cells.