Final answer:
A point mutation can result in a silent, missense, or nonsense mutation, affecting the amino acid sequence and consequently the function of the polypeptide produced from that gene. The specific impact depends on the roles of the amino acids involved and their chemical properties.
Step-by-step explanation:
A point mutation in a gene can affect the polypeptide product by leading to a change in the amino acid sequence. This can result in various types of mutations, such as silent, missense, or nonsense mutations, depending on the nature of the nucleotide change. In the case of the sequence provided, the mutation changes a triplet from ATC to ATG. We would need to use a codon chart to determine which amino acids these codons correspond to and assess the impact of the mutation. If ATC and ATG code for different amino acids, this substitution can lead to a missense mutation, which means the polypeptide would have an altered amino acid sequence. If the affected amino acid plays a critical role in the protein's function (like in the enzyme's active site) the mutation can significantly impact the protein's activity. However, if the new amino acid is chemically similar to the old one, the protein may still retain its function. A silent mutation has no effect since it does not change the amino acid due to the genetic code's redundancy.