Explain what happens if even one amino acid is substituted for another in a polypeptide chain. (Provide a specific example)

Mutation is a sudden heritable change in the DNA sequence that is transferrable from parent to offspring.

Substitution of amino acid is an example of mutation. It occurs when an amino acid is substituted for by another amino acid. It can lead to formation of new base sequence, protein or amino acid.

It leads to the alteration in the structure and function of amino acid. Example is the sickle cell aneamia which result from the substitution of glutamic acid by valine leading to a change of the Disc shape of Red blood cell to a Sickle shape leading to formation of sickle cell aneamia which causes serious health challenge to the carrier.