Amino Acid Formula: Definition, Types, Preparation

The amino acid formula is H2N-CH(R)-COOH, where "R" represents a variable side chain. Amino acids are the basic building blocks of proteins, each with a unique side chain determining their characteristics.

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Amino Acid Formula contains carbon, hydrogen, nitrogen, and oxygen elements. Some amino acids also contain other elements in their side chains. There are more than 500 amino acids in nature (only 20 of them appear in the genetic code), and we can classify them in several ways. In addition, amino acids have both amine and carboxyl acid groups attached to their first (alpha-) carbon atom in biochemistry.

Also Read : Avogadros Law

Amino Acid Formula and Structure

Amino acid formula

Amino acid molecules contain an organic R group, a central carbon atom to which an amino and a carboxyl group are linked, and a hydrogen atom in addition to the two bonds of the alpha-carbon. Represented by R-CH(NH2)-COOH, they weigh 110Da (Dalton), and take their name from α-amino carboxylic acids. The R group distinguishes each amino acid; unique chemical structures are found in this side chain.

Amino Acid Occurrence

It is the structural unit that makes up the proteins. They connect together to form short polymer chains known as peptides or even longer chains known as polypeptides or proteins. The polymers also have an unbranched and linear structure, where amino acids attach to neighboring amino acids in the chain.

A protein can contain non-proteinogenic amino acids that form by post-translational modification, which occurs after translation during protein synthesis. These modifications are often essential to the function or regulation of the protein.

Selenocysteine and pyrrolysine are non-proteinogenic amino acids that are not encoded directly by the codons of the universal genetic code.

Amino Acid Preparation

Besides serving as a building block for many important cellular molecules, amino acids also serve as a starting point for synthesizing vitamins and nucleotides. For the cell’s survival, amino acids must be synthesized or collected. Moreover, amino acids can be synthesized by one-step reactions from central metabolites. Their structure is also straightforward, and they are easy to synthesize as well.

Types of Amino Acids 

Basic amino groups (-NH2) and carboxyl groups (-COOH) are present in amino acids. There are twenty amino acids present that are responsible for the construction of proteins in peptides and proteins. The list of the 20 amino acids is provided below.

Types of Amino acid

These amino acids are:

  1. Alanine – ala – A
  2. Arginine – arg – R
  3. Asparagine – asn – N
  4. Aspartic acid – asp – D
  5. Cysteine – cys – C
  6. Glutamine – gln – Q
  7. Glutamic acid – glu – E
  8. Glycine – gly – G
  9. Histidine – his – H
  10. Isoleucine – ile – I
  11. Leucine – leu – L
  12. Lysine – lys – K
  13. Methionine – met – M
  14. Phenylalanine – phe – F
  15. Proline – pro – P
  16. Serine – ser – S
  17. Threonine – thr – T
  18. Tryptophan – trp – W
  19. Tyrosine – tyr – Y
  20. Valine – val – V

Essential and Non-Essential Amino Acids

Non-Essential Amino Acids: Our body can synthesize certain amino acids, known as non-essential amino acids. Examples include asparagines, aspartic acid, glutamic acid, proline, alanine, cysteine, glycine, serine and tyrosine.

Essential Amino Acids: Our bodies cannot naturally produce all of the 20 amino acids. Therefore, intake of food items with high protein content is necessary to provide these nine essential amino acids – methionine, threonine, valine, tryptophan, phenylalanine, leucine, histidine lysine and Isoleucine – to the body.

Functions of Amino Acid

Essential Amino Acid :

Essential Amino Acids have a range of important functions : 

  • Valine aids muscle growth. Threonine boosts the immune system; phenylalanine helps to maintain and improve memory power and a healthy nervous system, while lysine is necessary for forming hormones, enzymes, antibodies and stabilizing calcium in bones. 
  • Leucine facilitates protein synthesis and hormone production; methionine assists in treating kidney stones and skin health and wards off potential pathogenic bacteria. 
  • Tryptophan produces Vitamin B3 and serotonin, which controls appetite, regulates the sleep cycle, and encourages mood stability. 
  • Isoleucine enables the production of hemoglobin to carry oxygen from the lungs to other parts of the body; it also triggers insulin production by the pancreas. 
  • Lastly, histidine performs multiple enzymatic roles besides contributing to red and white blood cell manufacturing.

Non Essential Amino Acid : 

Non-Essential Amino Acids serve the following functions:

  • Our body uses cysteine as an antioxidant to provide resistance, inhibiting hair and nail growth.
  • Aside from removing toxins from the body, alanine helps produce glucose and amino acids.
  • In addition to maintaining proper cell growth and function, glycine also helps heal wounds and acts as a neurotransmitter
  • DNA and RNA are synthesized with glutamine, which is essential for brain function
  • It helps to produce proteins and hormones, detoxify the kidneys, maintain a healthy immune system, and heal wounds.
  • The human brain functions and develops due to glutamic acid’s role in neurotransmission.
  • Muscle growth and immune system protein synthesis are aided by serine
  • As well as synthesizing neurotransmitters, tyrosine is involved in the production of thyroid hormones, T3 & T4.
  • Purines and pyrimidines are formed from asparagines in order to form DNA, to transport nitrogen through cells, to develop the nervous system, and to increase our body’s stamina.
  • In addition to repairing tissues, proline helps form collagen, regenerates new skin, and prevents thickening and hardening of artery walls
  • The amino acid aspartic acid increases metabolism and promotes amino acid synthesis.

Amino Acid Properties

  • In addition to their optical isomerism, amino acids contain two ionizable groups: carboxyl and amino.
  • As a result of its carboxyl group, amino group, and radical R, it forms salts and undergoes decarboxylation in the presence of the carboxyl group. 
  • At room temperature and neutral pH, formaldehyde reacts with amino acid NH2 to form hydroxymethyl derivatives and the amino group is removed by deamination and transamination.

Amino Acid Uses

  • Amino acids have a wide array of uses in industries. 
  • They are frequently added as supplements to animal feed and serve as essential components, such as lysine, methionine, threonine and tryptophan, that may be absent or deficient in bulk feedstuffs like soybeans. Glutamic acid can be used as a flavor enhancer while aspartame is a low-calorie artificial sweetener. 
  • Additionally, the chelating potential of some amino acids is utilized in agriculture to facilitate plant nutrient absorption. 
  • In the pharmaceutical sector, certain amino acids are useful for treating depression.

Functions of Amino Acids

Essential Amino Acids perform the following functions:

  • Muscle growth is promoted by valine
  • The immune system is improved by threonine.
  • The amino acid phenylalanine boosts memory and maintains a healthy nervous system
  • The amino acid lysine plays a key role in the development and fixation of calcium in the bones, as well as hormones, enzymes, antibodies, as well as in the production of hormones, enzymes, and antibodies.
  • In the body, leucine promotes the synthesis of proteins and the growth of hormones
  • The amino acid methionine is beneficial for treating kidney stones, maintaining healthy skin, and invading pathogenic bacteria.
  • Among other things, tryptophan functions in the production of Vitamin B3 & serotonin hormones, which are responsible for maintaining appetite, regulating sleep, and boosting our mood.
  • It assists in the formation of hemoglobin, transports oxygen from the lungs to various parts of the body, and stimulates insulin synthesis in the pancreas.
  • The amino acid histidine plays a role in many enzymatic reactions and in the synthesis of RBCs and WBCs.

Non-Essential Amino Acids perform the following functions:

  • As an antioxidant, cysteine provides resistance to the body, inhibiting hair growth and nail growth.
  • The amino acid alanine assists in the removal of toxins from the body as well as the production of glucose.
  • Besides maintaining proper cell growth and function, glycine also functions as a neurotransmitter and aids in wound healing
  • For healthy brain function and for the synthesis of nucleic acids (DNA and RNA), glutamine is essential
  • As well as promoting the synthesis of proteins and hormones, arginine promotes the detoxification of kidneys, maintains a healthy immune system, and heals wounds.
  • Human brain development and functioning depend on glutamic acid for neurotransmission.
  • Muscle growth and immune system protein synthesis are assisted by serine
  • Tyrosine is involved in the production of thyroid hormones, T3 and T4, in the formation of melanin, which is the pigment found in hair, skin, and eyes, and in the synthesis of neurotransmitters.
  • The amino acid asparagine is essential to DNA synthesis, the transport of nitrogen in cells, the development of the nervous system, and improving our body’s stamina.
  • In addition to repairing tissues, proline helps in forming collagen, regenerating new skin and preventing artery walls from thickening and hardening.
  • The amino acid aspartic acid increases metabolism and promotes the synthesis of other amino acids.

Amino Acids Formula FAQ

What are amino acids?

Amino acids are organic molecules that serve as the building blocks of proteins. They consist of an amino group (NH2), a carboxyl group (COOH), and a variable side chain (R group).

How many essential amino acids are there?

There are nine essential amino acids that the human body cannot synthesize on its own and must be obtained through the diet.

What is the primary function of amino acids in the body?

Amino acids play a crucial role in protein synthesis, enzyme function, and numerous biological processes, serving as the basis for the structure and function of proteins.

Can amino acids be classified based on their side chains?

Yes, amino acids are classified into three groups based on the properties of their side chains: nonpolar (hydrophobic), polar (hydrophilic), and electrically charged (acidic or basic).

What is the significance of the genetic code in relation to amino acids?

The genetic code dictates the specific sequence of amino acids in a protein, with each three-letter codon in DNA corresponding to a particular amino acid, ensuring the accurate synthesis of proteins in cells.


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