This document summarizes the properties of 7 non-polar amino acids: glycine, alanine, proline, valine, leucine, isoleucine, and methionine. It describes their molecular structures, roles in proteins and metabolic pathways. Glycine is the smallest amino acid and participates in purine synthesis. Alanine transports ammonia from muscles to liver. Valine, leucine and isoleucine are branched chain amino acids, and their metabolism defects cause maple syrup urine disease. Proline has a cyclic side chain and causes protein folding. Methionine donates methyl groups and its metabolism impacts cardiovascular health.

1. Non- polar aminoacidic

2. Non- polar aminoacid includes:
• Glycine
• Alanine
• Proline
• Valine
• Lucine
• Isoleucine
• Methionine

3.  The molecular structure of NPAA:

4.  Glycine
• The smallest, simplest and lightest amino acid in the body
• It is the only amino acid that does not have an asymmetric carbon and does not have D
and L isomers and does not have optical activity
• Precursor of purine bases (adenine and guanine), heme, creatine and bile acids and
glutathione
• In the structure of proteins, glycine is mainly found in the β-turn site.
• Participating in the detoxification of chemical compounds such as benzoic acid, which
is added to food as a preservative, and converting it into hippuric acid (high solubility)
• Along with proline, it is one of the destabilizing amino acids of the alpha helix (-helixα)

5. Alanine
• As the most abundant amino acid in blood circulation
• Ammonia transporter from muscles to liver during severe starvation (glucose-alanine cycle)
• The most compatible amino acid to be placed in the alpha helix of proteins

6.  Valine, leucine and Isoleucine
• They are known as branched chain amino acids.
• Disturbance in the metabolism of branched amino acids (due to defects in the dehydrogenase
enzyme complex) causes maple syrup urine disease (MSUD).
• Isoleucine has 2 asymmetric carbon atoms
valine Lucine
Isoleucine

7.  Proline
• Proline is the cyclic form of glutamate.
• The alpha amine group of proline is of the second amine type, so it is called an imino acid.
• It has a cyclic structure in the side chain (not aromatic).
• Incompatible in alpha helix, compatible in β-turn (causes folding in the structure of proteins

8.  Methionine
• Along with ornithine, the precursor of polyamine compounds include spermidine and
spermine (polyamines in the cell are attached to anionic molecules such as DNA, which
helps to compact them).
• The active form of methionine (S-adenosylmethionine or SAM), which acts as a methyl group
donor in some biochemical reactions
• This compound has purine in its structure.
• Methionine is converted to homocysteine by loss of methyl
• Increasing the concentration of homocysteine in the blood is a risk factor for cardiovascular
diseases