Question

g A polypeptide has the following amino acid sequence: Met-Ala-Gln-Arg-Glu-Leu. This polypeptide was mutated to produce the following mutant sequence: Met-Ala- Gln-Gly-Glu-Leu. Which describes the MOST likely type of mutation that occurred? A) nonsense mutation B) missense mutation C) frameshift mutation D) loss-of-function mutation E) neutral mutation

Answer 1

Answer:

B) missense mutation

Explanation:

Missense mutation can be defined as the genetic mutation whereby a change occurs in a single amino acid sequence of a protein.

A missense mutation is a error that is observed in the DNA which is as a result of a wrong amino acid being added to into a protein because of change that was experienced. That single DNA sequence change, results in the formation of a different amino acid codon which the ribosome in living organisms recognizes.

Missense mutation is not a harmful mutation.

Answer 2

Answer:

B) missense mutation

Explanation:

A type of base substitution that results in the replacement of one amino acid by another is called missense mutation. Missense mutations affect the mutated proteins in several ways. It may alter the amino acid composition of the active site of enzymes and render the enzymes inactive.

The wild type polypeptide chain has the following sequence of amino acids: Met-Ala-Gln-Arg-Glu-Leu. The mutated polypeptide has glycine in place of arginine. The rest of the amino acids are the same in wild type and mutated protein. This means that the mutation changed the genetic code of arginine into the genetic code of glycine resulting in the incorporation of glycine in position 4. This is an example of a missense mutation.