Question

he stability of DNA is affected by the number of hydrogen bonds, with more bonds promoting more stability. The double-stranded DNA molecule you would expect to have the greatest stability would be one with _____% _____.

Answer 1

Answer:

• Ideally, the answer is 100% GC content, but this percentage is not observed in any living organism.
• GC content in living organisms can be less than 30% or more than 80%.
• The DNA having greater than 80% GC content is considered to be stable.

Explanation:

• The stability of a double -stranded DNA molecule depends on the number of hydrogen bonds present in between the double helix.
• Hydrogen bonds are formed between the purine (A,G) and pyrimidine (T,C) nitrogenous bases.
• Adenine (A) and Thymine (T) - two hydrogen bonds.
• Guanine (G) and Cytosine (C) - three hydrogen bonds.
• So the DNA double helix having more GC content will have more hydrogen bonds and hence would be more stable.
• The GC content in a DNA molecule is determined by the ratio of the number of GC bonds present in the DNA to the total number of bonds (AT and GC) present.
• DNA with more than 80% GC content is most stable.