The relative strength of hydrogen bonding between nitrogenous bases is: Stronges
ID: 58343 • Letter: T
Question
The relative strength of hydrogen bonding between nitrogenous bases is:
Strongest G-C > A-T > A-U Weakest
You have four double-stranded nucleic acid molecules, all of which are 100 nucleotides long. Which do you expect will be the MOST STABLE (least likely to become entirely single-stranded) at high temperatures?
A. An RNA double helix with 20% cytosine
B. An RNA double helix with 20% adenine
C. A DNA double helix with 30% cytosine
D. A DNA double helix with 30% adenine
E. Can’t determine from the information given
Explanation / Answer
In gene base pairing, the guanine (G)- cytosine (C) molecules are connected together by three hydrogen bonds. It is the strongest than A-T and A-U. Adenone (A) and Thymine (T) are connected together by two hydrogen bonds, adenine and uracil (U) are also connected together by two hydrogen bonds. But thymine contains one methyl group, which reduces the bond strength to some extent. Thus,
Strongest G-C > A-U > A-T Weakest