Question

What effect does the mutation have on the protein?
Responses
A Phe replaces Leu in the amino acid sequence.Phe replaces Leu in the amino acid sequence.
B Lys replaces Asn in the amino acid sequence.Lys replaces Asn in the amino acid sequence.
C Leu replaces Phe in the amino acid sequence.Leu replaces Phe in the amino acid sequence.
D Asn replaces Lys in the amino acid sequence.

Answer 1

I don’t have the mutation or sequence information needed to pick A–D. Give me the original and mutated DNA (or the codon change, or the mRNA/codon before and after the mutation) and I’ll tell you which amino acid is replaced.

If you want to check yourself, here’s how to determine the effect:
1. Identify the codon that changed (three bases).
2. If you have DNA, transcribe to mRNA (replace T → U).
3. Use the codon table to translate the original and mutated codons to amino acids. Common codons to help:
- Phe (F) = UUU, UUC
- Leu (L) = UUA, UUG, CUU, CUC, CUA, CUG
- Lys (K) = AAA, AAG
- Asn (N) = AAU, AAC
4. Compare the two amino acids:
- If they’re the same → silent (no change in protein sequence).
- If different → missense (one residue replaced by another).
- If changed to a stop codon (UAA, UAG, UGA) → nonsense (truncated protein).

Paste the mutation (e.g., DNA: GAA → GUA, or codon change UUU → UUA) and I’ll choose A–D for you.