Explain why the structure and function of proteins is essential to living organisms.

Authors Avatar

Matt Wilkinson                

Explain 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

    |

    NH2

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.

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.

Join now!

Secondary structure is slightly more complex than Primary. This refers to the way the polypeptide chains are twisted and folded due to hydrogen bonding. Within Secondary structure there are two types of bonding: Alpha Helix and Beta pleating.

Alpha helix proteins are twisted into an alpha helix formation by hydrogen bonds forming between different amino acids. This happens as the hydrogen bonds are not long enough to reach the amino acids in the linear, primary structure and so they force polypeptide chain into the new structure. This provides a stronger more stable structure than a ...

This is a preview of the whole essay