We are given a DNA sequence and its exposed mutation, then asked to determine the mRNA sequence and consequential amino acid sequence. Here is a step-by-step analysis for each part of the problem:
### Part 1: Identify the sequence of complementary mRNA nucleotides
Original DNA: ATG
To find the mRNA sequence, we need to replace each T in the DNA sequence with U:
- A in DNA pairs with U in mRNA.
- T in DNA pairs with A in mRNA.
- G in DNA pairs with C in mRNA.
Thus, the original mRNA sequence is:
- A -> U
- T -> A
- G -> C
Therefore, the original mRNA sequence corresponding to the original DNA sequence (ATG) is AUG.
Mutated DNA: ATA
Using the same pairing rules to determine the mRNA sequence:
- A in DNA pairs with U in mRNA.
- T in DNA pairs with A in mRNA.
- A in DNA pairs with U in mRNA.
Thus, the mutated mRNA sequence is:
- A -> U
- T -> A
- A -> U
Therefore, the mutated mRNA sequence corresponding to the mutated DNA sequence (ATA) is AUA.
### Part 2: Determine if this mutation in the DNA code will cause a change in the amino acid
Now, we use the provided codon table to determine the amino acid sequences for the original and mutated mRNA sequences.
Original mRNA (AUG):
- According to the codon table, AUG codes for "Met(Start)".
Mutated mRNA (AUA):
- AUA codes for "Ile".
By comparing the amino acids:
- The original mRNA sequence (AUG) translates to "Met(Start)".
- The mutated mRNA sequence (AUA) translates to "Ile".
Since "Met(Start)" and "Ile" are different amino acids, the mutation results in a change in the amino acid sequence.
### Conclusion
The mutation from ATG in the original DNA to ATA in the mutated DNA changes the mRNA sequence from AUG to AUA. This substitution alters the encoded amino acid from "Met(Start)" to "Ile". Hence, the mutation causes a change in the amino acid sequence.
