Proteins and Nucleic Acids, The Protein Structures

Proteins and Nucleic Acids
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Proteins and Nucleic Acids
Proteins
Proteins are organic compounds found in the cells of a living organism. They make approximately 50% of the dry mass of the majority of the cells of a living organism. Proteins play numerous roles in the body. Some of the roles played by the proteins include offering structural support, transport, and storage, and acting as a medium of cellular communications. Moreover, proteins are also involved in the movement, and in defending the body against pathogens.
Proteins Structure
Proteins are primarily comprised of amino acid chains. There are twenty naturally occurring amino acids, that can be amalgamated in many different ways. An arrangement of the amino acids determines the general shape of a given protein. The shape of a given protein molecule is the determinant of its main role (Wüthrich, 1986).
Levels of the Protein Structure
A normal protein structure is usually one of the four known levels. The primary structure defines the amino acid sequence in a given protein. It is usually arbitrated by the sequence of the Deoxyribonucleic Acid in the nucleus of a cell. The second level of the protein structure is known as the secondary structure. It defines the coiling of the overall protein chain. It occurs as a result of the action of the hydrogen bonds that links varying amino acids together. The secondary structure constitutes of the spiral shape and the folded sheet.
Tertiary protein structure is the third level of the protein structures. It forms the real three-dimensional shape of protein. It arises as a result of the interactions between bonds in a protein molecule. These bonds include hydrogen, disulfide, ionic, and the Van der Waals bonds. The disulfide bonding usually occurs within sulfur atoms in a molecule. Sulfur bonding gives the hair its natural coiling and a bad smell when burnt. Sometimes a small number of the amino acid molecules combines to form small proteins called polypeptides. Two or more polypeptides comprising of different shapes amalgamate to form a quaternary protein structure. The hemoglobin molecule is a good example of the quaternary protein structure ((Wüthrich, 1986).
Determinants of the Protein Conformations
Various factors alter the typical structure of the proteins. Some of these factors are proteins and the pH. Change is the normal levels of pH or temperatures bring about denaturing of the protein, which is an abnormal change in the protein structure. A change in the protein structure inactivates it biologically. The denaturatio...