Answer:
The effect on proteins depends on the type of mutation. Mutations in the mRNA could lead to alterations in the sequence of amino acids in the protein. These alterations could be silent or they can also lead to severe genetic abnormalities.
Explanation:
Point Mutation:
A point mutation in the DNA or RNA alters a single nucleotide base in the DNA sequence. Point mutations are of three types:
- Substitution: When a base is substituted for another. This has further 3 types:
A mutation that substitutes one base for another in such a way that the new sequence forms a new codon that is not a stop codon. For example, if the nucleotide sequence changes from AAG to AGG, the amino acid arginine will be produced instead of lysine.
Nonsense mutation substitutes a codon for an amino acid with a stop codon. This kind of mutation produces a truncated or incomplete protein that is nonfunctional.
A mutation that alters the genetic code in such a way that another codon for the same amino acid is produced, rendering no difference to the protein.
2. Insertion: involves the insertion of a new base in the nucleotide sequence.
3. Deletion: Involves the deletion of a base from the DNA sequence.
Point mutations, particularly, insertions, deletions and missense mutations can result in truncated or nonfunctional proteins that are unable to perform cellular functions. Cystic fibrosis and sickle cell anemia are prime examples of disorders caused by point mutations.
