what is protein synthesis?

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Proteins have diverse functions in the body and the body cells have the inherent ability to make them.

Living cells have evolved around their ability to produce proteins for their functions and growth. Right from the unicellular organisms to complex higher animals like mammals, all have the ability to make them from the amino acids present in the cytoplasm.

What is protein (polypeptide) synthesis?

All biological processes involve proteins present in the living cells. They are also essential nutrients for all life forms for their functions; Most of them are made by the body. There are many other uses of for them outside the body. Polypeptides are also manufactured by different chemical methods. These protein production processes inside the body as well as polypeptide manufacture chemically are broadly called protein synthesis.

What is protein bio-synthesis?

All organisms grow and reproduce. For these functions they have to utilize the nutrients and convert them into cell structures and body structures; the basis of which is protein. The body requires great number of them (1000s) for its many facets of activity. To directly source all these and use them is an impossible task for a living organism.

The body does not absorb the polypeptides as such but absorbs its broken down form as amino acids. The living body also has the capacity to make many of the amino acids. Amino acids numbering 22 constitute by their sequences and structural alignments all forms of polypeptides. With the exception of the unicellular organisms all the the higher organisms have nucleus in their cells (exception being red blood cells in many mammals). The cell nucleus contains specific numbers of chromosomes which are again specific to the particular organism. The chromosomes are in-turn made of DNA molecules.

part of a DNA double helix The DNA has the code for synthesis of polypeptides. By a complex process of bio-signals, the cell gets a message for the production of a particular molecule in certain quantity. Then a complex process occurs both inside and outside the cell nucleus giving rise to strands of polypeptides. This process is called protein bio-synthesis. The process and steps involved are discussed in post 'Protein synthesis steps and process'.

What is peptide synthesis?

Apart from the long strands of peptides formed by ribosomes inside the cells, biologically peptides are also produced outside the cells. The milk peptides are produced by enzymatic breakdown of milk protein by digestive enzymes as well as enzymes formed by lactobacilli. In non-biological process of peptide production short peptides are produced in laboratories. There are two types of peptide production methods namely liquid phase production and solid phase synthesis. A subject of great research interest is the synthesis of peptide antibodies.

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Vitamin C in collagen synthesis

Home › Nutritional deficiency › Vitamin C - Collagen synthesis

Vitamin C (ascorbic acid) is required for collagen synthesis, a vital protein component of connective tissue.

Collagen is a unique type of protein required by almost all organs of the body and the synthesis of which depends on vitamin C availability. It is the abundant protein in the human body, makes up to 30% of its protein content. In the skin 75% of the dermis is made up of it. Vitamin C plays an important role as cofactor in its formation. There is synthesis of 29 of its types identified so far in the body. Out of these four are main types making up 90% of the body connective tissue.

Type 1: This is for the formation of skin, organs, bone matrix, ligaments, tendons and blood vessels.
Type 2: This is for the formation of cartilage.
Type 3: This is for the formation of the reticular fibres.
Type 4: This is for the formation of Cell basement membrane.
Type 5: this is for the formation of Cell surfaces, placenta and hair.
Vitamin C deficiency affects the assembly, secretion, or other biological processes involved in the production of this vital protein.

Vitamin C in Collagen synthesis

Collagen has unique amino acid composition depending upon the type of tissue formed. Amino acid Glycine (Gly) is found at almost every third place and amino acids Proline (Pro) and its derivative Hydroxyproline makes up about 10% of this protein. Proline and hydroxyproline play key role in the stability of this protein by helping the twist of helix.

In the higher organisms like humans, for maintaining the connective tissue, critical and crucial biochemical process is hydroxylation of proline.
Its synthesis for increasing its conformational stability significantly, hydroxylation of the amino acid proline by the enzyme prolyl hydroxylase is required.
Ascorbic acid is a necessary cofactor in this biochemical process.

Vitamin C (ascorbic acid) and enzyme catalysed reactions occurs in the lumen present in the endoplasmic reticulum.
Lack of this ascorbic acid (ascorbate) cofactor results in defects in this hydroxylation and mutations in the enzyme prolyl hydroxylase affecting the protein and its proper formation.
Vitamin C in collagen synthesis process more than serving as catalyst gets destroyed by donating H atom in the critical process of assembling this protein in the tissues.

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