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Consider the following portion of mRNA produced by the normal order of DNA nucle

ID: 1017932 • Letter: C

Question

Consider the following portion of mRNA produced by the normal order of DNA nucleotides: Write the amino acid sequence that would be produced from this mRNA. Write the amino acid sequence if a mutation changes UCA to ACA. Is this likely to affect protein function? Write the amino acid sequence if a mutation changes CGG to GGG. Is this likely to affect protein function? What happens to protein synthesis if a mutation changes UCA to UAA? What happens to the protein sequence if a G is added to the beginning of the chain and the sequence changes to 5'GAC|AUC|ACG]GGU3'.' What happens to the protein sequence if the A is removed from the beginning of the chain and the sequence changes to 5 'CAU | CAC | GGG3?

Explanation / Answer

1. 5' ACA UCA CGG GUA 3' gives the protein with sequence Thr-Ser-Arg-Val

2. In the above sequence if UCA is replaced by ACA the protein sequence will be Thr-Thr-Arg-Val

3. In the above sequence if CGG is replaced by GGG the protein sequence will be Thr-Ser-Gly-Val

4. In the above sequenceif UCA is replaced by UAA the protein chain will be stopped as UAA is a termination codon. No protein is produced

5. 5' GAC AUC ACG GGU 3' gives the protein with sequence Asp-Ile-Thr-Gly

6. 5' CAU CAC GGG 3' gives the protein with sequence His-His-Gly