Biology – Protein synthesis | e-Consult

A mutation in a gene can alter the DNA sequence, leading to a change in the mRNA codon. This, in turn, can affect the amino acid sequence of the polypeptide. The consequences of this change depend on the type of mutation:

• Silent mutation: This is a change in the codon that does not alter the amino acid sequence. This may have no effect on the polypeptide's structure or function.
• Missense mutation: This is a change in the codon that results in a different amino acid being incorporated into the polypeptide. The effect on the polypeptide's structure and function depends on the nature of the amino acid change. If the new amino acid has similar chemical properties to the original, the effect may be minimal. However, if the new amino acid has very different properties, it could disrupt the protein's folding, stability, or ability to interact with other molecules, leading to a loss or alteration of function.
• Nonsense mutation: This is a change in the codon that results in a stop codon. This leads to premature termination of translation, resulting in a truncated (shortened) polypeptide. This truncated polypeptide is often non-functional or unstable.

The impact of a mutation can range from no noticeable effect to a complete loss of function, depending on the location and nature of the mutation and the importance of the affected amino acid in the polypeptide's structure and function. Even a single amino acid change can have significant consequences for protein folding, stability, and interactions with other molecules.