AMINO ACIDS

Amino acids are the building blocks that form polypeptides and ultimately proteins. Consequently, they are fundamental components of our bodies and vital for physiological functions such as protein synthesis, tissue repair and nutrient absorption. Three nucleotides form codons that code for amino acids.

The four nucleotides can produce a total of 64 different combinations of codons from these 61 represent amino acids and the remaining 3 are stop codons. Amino acids are classified into 3 groups :-

• Essential amino acids
• Non-essential amino acids
• Conditional amino acids

Amino acids are compounds that are made up of oxygen, nitrogen, carbon and hydrogen.

ESSENTIAL AMINO ACIDS

Essential amino acids cannot be made by the body. As a result, they must come from food. The 9 essential amino acids are: histidine, isoleucine, leucine, lysine, methionine, phenylalanine, threonine, tryptophan, and valine.

NONESSENTIAL AMINO ACIDS

Nonessential means that our bodies can produce the amino acid, even if we do not get it from the food we eat. Nonessential amino acids include: alanine, arginine, asparagine, aspartic acid, cysteine, glutamic acid, glutamine, glycine, proline, serine, and tyrosine.

CONDITIONAL AMINO ACIDS

Conditional amino acids are usually not essential, except in times of illness and stress. Conditional amino acids include: arginine, cysteine, glutamine, tyrosine, glycine, ornithine, proline, and serine.

There are 20 amino acids that make up proteins and all have the same basic structure, differing only in the R-group or side chain they have.

They can be subdivided according to their properties, dictated by the functional groups they possess. Broadly they are divided by charge, hydrophobicity and polarity. These properties influence the way they interact with surrounding amino acids in polypeptides and proteins, and consequently impact protein 3D structure and properties.