Question

Which of the following DNA molecules is the most thermodynamically stable?

A. 5'GGGGAAAACCCCTTTT 3'
B. 5'AGCGCGCAGCGTTTTT 3'
C. 5'AAAGGAATTCCGTTAA 3'
D. 5'GCATCGAGGCCGGCTG 3'

Answer 1

The most thermodynamically stable DNA molecule is the one with the highest GC content. Therefore, option D (5'GCATCGAGGCCGGCTG 3') with a GC content of 65% is the most thermodynamically stable DNA molecule.

Step-by-step explanation:

The most thermodynamically stable DNA molecule is the one with the highest GC content. GC base pairs are bound by three hydrogen bonds, while AT base pairs are bound by two hydrogen bonds. Therefore, a DNA molecule with a higher GC content will have more stable base pairing and be more thermodynamically stable.

Let's analyze the given options:

1. Option A (5'GGGGAAAACCCCTTTT 3') has a GC content of 0%.
2. Option B (5'AGCGCGCAGCGTTTTT 3') has a GC content of 50%.
3. Option C (5'AAAGGAATTCCGTTAA 3') has a GC content of 0%.
4. Option D (5'GCATCGAGGCCGGCTG 3') has a GC content of 65%.

Based on the analysis, option D (5'GCATCGAGGCCGGCTG 3') with a GC content of 65% is the most thermodynamically stable DNA molecule.