Which of the following is MOST responsible for maintaining the double-stranded structure of
DNA?
A. Attractive interactions between positively charged purines and negatively charged
pyrimidines.
B. Hydrogen bonding between the 3\'-OH of deoxyribose and purine and pyrimidine ring
nitrogens.
C. Hydrophobic interactions between contiguous base pairs and hydrogen bonding between
complementary bases on opposite strands.
D. Interactions between the phosphate groups in separate chains.
E. Hydrophilic interactions between the pentoses in separate chains.
Solution
A. Attractive interactions between positively charged purines and negatively charged
pyrimidines.
Explanation- Attractive interactions between partial positive charge on purines and partial
negative charge on pyrimidines is responsible for maintaining stability of DNA.
Hydrogen bonds in the DNA strands are individually weak but are collectively strong. These
bonds between complementary base pairs stabilize the helical structure of DNA.
Adenine is paired through two hydrogen bonds with thymine. Guanidine is paired through three
hydrogen bonds with cytosine..
Graduate Outcomes Presentation Slides - English (v3).pptx
Which of the following is MOST responsible for maintaining the doubl.pdf
1. Which of the following is MOST responsible for maintaining the double-stranded structure of
DNA?
A. Attractive interactions between positively charged purines and negatively charged
pyrimidines.
B. Hydrogen bonding between the 3'-OH of deoxyribose and purine and pyrimidine ring
nitrogens.
C. Hydrophobic interactions between contiguous base pairs and hydrogen bonding between
complementary bases on opposite strands.
D. Interactions between the phosphate groups in separate chains.
E. Hydrophilic interactions between the pentoses in separate chains.
Solution
A. Attractive interactions between positively charged purines and negatively charged
pyrimidines.
Explanation- Attractive interactions between partial positive charge on purines and partial
negative charge on pyrimidines is responsible for maintaining stability of DNA.
Hydrogen bonds in the DNA strands are individually weak but are collectively strong. These
bonds between complementary base pairs stabilize the helical structure of DNA.
Adenine is paired through two hydrogen bonds with thymine. Guanidine is paired through three
hydrogen bonds with cytosine.
