Amino Acids

Amino acids are regarded as “building blocks” for their significance in protein synthesis. Biological and chemical processes in the human body rely heavily on these biomolecules, and they are essential for all phases of life’s growth and development. The number of different amino acids in nature is estimated to be around 300.

Amino Acids

There are both basic (-NH₂) and carboxyl (-COOH) elements in a protein’s amino acid structure (-COOH). Amino acids are the building blocks of proteins. The amino acid chains that makeup peptides and proteins are quite long and comprise several amino acids. Each of the twenty amino acids has a role in synthesising proteins. Proteins are macromolecules of amino acids with a large molecular mass and are present in all living cells.

Amino Acid Sources

Enzymes, digestion, molecular transport, and many other activities are dependent on amino acids for their production and action. Essential amino acids must be supplied from protein-rich meals every day since our bodies can only manufacture a limited quantity of amino acids. In terms of amino acid content, soybeans are among the best sources. There are a lot of amino acids in fruits and vegetables such as these. They may be found in large quantities in dairy products and eggs, as well as meat such as chicken and beef.

Classification of Amino Acids

• Classification Based on Body Requirements

1. Non-Essential Amino Acids

We do not need to consume these amino acids since our bodies produce them. Ten of the twenty amino acids are unnecessary. Glycine contains all of these amino acids, as well as serine, cysteine, glutamine, tyrosine, and proline.

2. Essential Amino Acids

Our bodies cannot synthesise some amino acids on their own. Thus we must obtain them from the diet. Ten of the twenty amino acids are unnecessary. The human body contains these amino acids: valine, threonine, arginine, lysine, phenylalanine, and histidine. Kwashiorkor is a disorder caused by a lack of particular amino acids required for normal body growth and development.

Classification based on the Occurrence

Aliphatic, aromatic, and heterocyclic amino acids are all naturally occurring and can be categorised into three classes.

• Aliphatic Amino Acids

The amino acids are long-chained. The following amino acids are further subdivided:

• Neutral Amino Acid

It has equal numbers of carboxylic and amino groups in its molecules. Glycine, alanine, valine, and other amino acids are examples of neutral amino acids.

• Acidic Amino Acid

Acidic amino acids have a higher concentration of carboxylic groups than amino groups.

Aspartic acid and glutamic acid, which have two –COOH groups and one –NH₂ group, are examples of this acid type.

• Basic Amino Acid

Carboxylic compounds have a lower number of amino groups than amino groups.

Examples include lysine, arginine, and histidine, including two –NH₂ groups and two –COOH groups.

• Sulphur Containing Amino Acid

They have sulfhydryl groups (–SH) in their structure, which make them sulphur-containing amino acids

e.g., cysteine and methionine.

• Aromatic Amino Acids

A benzene ring is present in the structure of aromatic amino acids.

e.g., tyrosine and phenylalanine.

• Heterocyclic Amino Acid

A heterocyclic ring containing at least one atom other than carbon in the side chain is required for heterocyclic amino acids.

E.g., tryptophan, proline, and hydroxyproline 

Role of Amino Acids in the Human Body

• Molecules with biological activity may be made from amino acids

• Example: tyrosine that converts into hormones thyroxine and adrenaline, and the pigment melanin that appears on the surface of your skin

• Glycine assists in the production of haeme (a protein found in haemoglobin) and tryptophan when coupled with the vitamin nicotinamide and the plant hormone indole acetic acid

• Amino acids are known as citrulline and ornithine play a key role in the urea cycle in the liver, which helps to keep ammonia levels in the blood from spiking to dangerous levels

Features of Amino Acid

• They are crystalline compounds that are colourless and odourless

• They have a high melting point, making them ideal for melting plastics

• The nature of the side chain affects the solubility of the compound in water

• They are amphoteric and react with both acids and bases simultaneously

• Except for glycine, all have asymmetric carbon, which causes polarised plane light to spin

• Optical activity is the term used to describe this feature

Conclusion

As a group of neutral products, amino acids are distinguished from other natural compounds both chemically, primarily due to their ampholytic properties, and biochemically, primarily due to their role as protein constituents. Amino acids are also distinguished from other natural compounds in their ampholytic properties, mainly responsible for their ampholytic properties. As defined by the International Union of Chemical Sciences and Technology, amino acids are carboxylic acids having an aliphatic primary amino group located in the position of the carboxyl group and with a particular stereochemical property. Proteins are biosynthesised from 20 amino acids in a strictly controlled manner by genetics. Proteins are made up of amino acids, which serve as the fundamental building block. More than 300 amino acids can be found in nature; however, only 20 amino acids are standard and present in protein since they are encoded by genes and are thus present in the protein itself.