To transcribe and translate the given DNA strand into mRNA and then into a polypeptide chain, follow these steps:
1. Transcription
The first step is to transcribe the DNA sequence into mRNA. DNA is transcribed into mRNA by replacing each thymine (T) with uracil (U). The given DNA strand is:
DNA Strand: A T A C G A A A T C G C G A T C G C G G C G A T T C G G
Transcribing this will result in:
mRNA Strand: U A U G C U U U A G C G C U A G C G C C G C U A A G C C
2. Translating mRNA to a Polypeptide
Next, we translate the mRNA into a polypeptide chain by dividing the mRNA into codons (groups of three nucleotides). Here are the mRNA codons:
- UAG
- CUU
- AGC
- GCU
- AGC
- GCC
- GCU
- AAG
- CC
Using a codon table, we can see which amino acids correspond to these codons:
- UAG – Stop
- CUG – Leucine (Leu)
- AGC – Serine (Ser)
- GCU – Alanine (Ala)
- GCC – Alanine (Ala)
- GCU – Alanine (Ala)
- AAG – Lysine (Lys)
Putting it all together, the polypeptide chain is as follows:
Amino Acid Sequence: Stop – Leu – Ser – Ala – Ala – Ala – Lys
Conclusion
In summary, by transcribing the given DNA strand into mRNA and then translating that mRNA into a polypeptide sequence, we identified the corresponding codons and resulting amino acids. This process is fundamental in molecular biology and genetics.