Amino acids are the building blocks of proteins. Approximately 500 of them exist, but only 20 appear in our genetic code. Those shown below are known as standard amino acids. Use the following as a …

Amino acids with a polar (hydrophilic) neutral side chain (at pH = 6): serine, threonine, cysteine, tyrosine, asparagine, glutamine. These amino acids are more soluble in water than the non-polar amino acids, …

All of the proteins on earth are made up of the same 20 amino acids. Linked together in long chains called polypeptides, amino acids are the building blocks for the vast assortment of proteins found in …

Unlike most organic compounds, amino acids are soluble in water, have either high melting points or decompose upon heating. They act more like inorganic materials than organic compounds.

These amino acids have side chains that do not form hydrogen bonds with water, making them hydrophobic. They are often found in the interior of proteins, away from water.

Note: This chart only shows those amino acids for which the human genetic code directly codes for. Selenocysteine is often referred to as the 21st amino acid, but is encoded in a special manner.

Amino Acids: Classification The 20 amino acids found in proteins can be placed in five families based on the physical and chemical properties of their R groups: