Proteins : A Major Molecular Constituent Of Cells

1129 Words Oct 27th, 2015 5 Pages
Proteins are a major molecular constituent of cells they are vital for all living organisms and make up about 15% of body mass. They are versatile macromolecules as they serve as a catalyst for biochemical reactions (Hayward, 1999).

Amino acids are amphoteric and are the flat form of proteins. Only twenty occur in those proteins found in humans (Nelson et al., 2008). Molecules called polymers link together in repeating units and form to become a protein. Proteins frame structural and motor elements in the cell and each protein and are the end product of the decoding process, which starts with the information in DNA and has its own function determined by its gene (Alberts, 2002). Figure 1. Imagine showing the twenty amino acids occurring in proteins (Particlesciences.com, 2015).

Proteins fall into two groups which are globular and fibrous. Globular proteins are mostly enzymes which are high folded. Fibrous proteins however are typically structural (Chemguide.co.uk, 2015). Their role is to give cells and tissues structural integrity and strength (Crowe and Bradshaw, 2014).

Protein chains arrange themselves to maximise the intro and intermolecular bonding. Various protein shapes are folded into three dimensional structures into a conformation of lowest energy. The forces driving protein folding are, hydrophobic groups, hydrophilic groups, charged side chains and cysteine residues (Rich, 1955). Proteins can unfold and this process is called denaturation. This happens at…
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