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Why the Structure and Function of Proteins is Essential to Living Organisms

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Why the Structure and Function of Proteins is Essential to Living Organisms Proteins, along with carbohydrates, lipids and nucleic acid make up all life on earth, and without any one of these macromolecules, life on earth would not be able to continue. Proteins consist of amino acids joined together via peptide bonds to form polypeptides. There are 20 natural amino acids without which proteins couldn't exist. COOH | H-C-R | NH 2 Above is the general structure of an amino acid, the R represents the variable group, which varies with each amino acid, and affects the properties and behaviour of each amino acid. To form a protein the amino acid must bond with at least one other amino acid, forming a peptide bond. [IMAGE] As shown in the diagram Amino acids bond to form proteins which can bond with other amino acids or other proteins to form new proteins, therefore there is an infinite number of proteins which can be formed, each one having its own structure and function within living organisms. (1) (2) (3) There are four levels of construction within proteins and which level the protein is at determines the structure and function of that particular protein. The four levels are: Primary, Secondary, Tertiary and Quaternary. Primary structure makes up the most simple proteins, These fibrous proteins are made up of simple polymers of amino acids and are generally very long. They consist a polypeptide backbone running down the peptide bonds with the variable groups jutting out to the sides, as demonstrated in the diagram below. diagram of a polypept... ... middle of paper ... ...at, pressure and acidity. If the temperature rises excessively or the globular protein is put under immense pressure kinetic energy within the molecule will increase causing vibrations within the molecule to increase also. Eventually the hydrogen bonds holding protein in its 3D shape break irrevocably causing the molecule to 'unfold' and lose its shape. Also excess acidity causes the hydrogen bonds to break and has the same effect as excess heat. This is known as de-naturation of the protein. When this happens the proteins can no longer perform their functions because they no longer have the structure to do so; the key no longer fits the lock. This further proves a direct link between structure and function in that when the structure is proved even minutely, the protein can no longer carry out its metabolic function.
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