Unit 1: Topic 6 - Nucleic Acids

Question 1

What are the structural similarities between DNA and RNA?

Answer 1

Both have a sugar, a phosphate group, and a nitrogenous base that form nucleotides. Both DNA and RNA have the nitrogenous bases adenine, guanine, and cytosine. These nucleotides form a linear molecule with a 5’ (phosphate) end and a 3’ (hydroxyl) end. The nucleotides are connected perpendicularly to the sugar phosphate backbone to form a DNA or RNA strand.

Question 2

List 3 structural differences between DNA and RNA

Answer 2

1. DNA contains deoxyribose, while RNA instead contains ribose (both are 5-carbon sugars).
2. RNA contains uracil, while DNA instead contains thymine (both are nucleobases).
3. DNA is usually double-stranded, and RNA is usually single-stranded.

Question 3

How are DNA strands oriented?

Answer 3

The two strands are antiparallel with respect to each other. They are aligned but have opposite directionality (the 5’ end of one strand matches with the 3’ end of the other strand).