Which type of mutation results in a different amino acid being incorporated into a protein?

A missense mutation is a type of genetic alteration that leads to a change in a single amino acid in a protein sequence. This occurs when a change in a single nucleotide results in the codon coding for a different amino acid, rather than the original one. Such changes can have various effects on the protein, depending on the role of the altered amino acid in the protein's structure and function. If the new amino acid is similar to the original, the impact might be minimal, but if it significantly alters the chemical properties or shape of the protein, it could affect the protein's activity or stability.

The presence of a missense mutation highlights how even small changes at the DNA level can have meaningful consequences for protein synthesis and, consequently, for an organism's biology. This mutation type contrasts with silent mutations, which do not alter the amino acid sequence despite a nucleotide change, thus having no effect on the resulting protein. Nonsense mutations introduce a premature stop codon, leading to truncated proteins, and base substitution mutations could refer to both missense and silent mutations without specifying the outcome regarding amino acid change. Therefore, a missense mutation specifically identifies the type that results in a different amino acid being incorporated into a protein.