Read the given statements and select the correct option.
Statement 1 : Haemoglobin is an example of quatemary structure of proteins.
Statement 2 : Haemoglobin molecule is composed of four polypeptide chains-two`alpha`-chains and two `beta`-chains.

Options

A. Both statements 1 and 2 are correct.
B. Statement 1 is correct but statement 2 is incorrect.
C. Statement 1 is incorrect but statement 2 is correct.
D. Both statements 1 and 2 are incorrect.

Answer

A

Explanation

Proteins are said to have quaternary structure if they consist of 2 or more polypeptide chains untied by force other than covalent bonds (i.e., not peptide are hydrogen bonds). The force that stabilise these aggregates are hydrogen bonds and electrostatic bonds formed between amino acids on the polypeptide chains. Haemoglobin, the oxygen-transporting protein of blood, is an example of quaternary structure. This protein consists of four peptide chains of two types-`alpha` and `beta` chains that occur in pairs.