Nucleotides and Nucleic Acids

Question 1

What are nucleobases?

Answer 1

contain a nitrogenous base

Question 2

What is a nucleoside?

Answer 2

Nitogenous base and a pentose sugar

Question 3

What is a nucleotide?

Answer 3

Nitrogenous base, a pentose sugar, and a phosphate (always on the 5’ carbon).

Question 4

What are the prymidines?

Answer 4

Cytosine, Thymine, and Uracil in (RNA)

Question 5

What are the purines?

Answer 5

Adenine and Guanine.

Question 6

What is the overall structure of DNA?

Answer 6

It contains a negative backbone. Has double strands that wrap around each other. They are anti-parallel strands so one runs 5’-3’ and the other runs 3’-5’. There is complementarity between the strands. A right handed helix.

Question 7

What interactions stabilize the DNA double helix?

Answer 7

Syn and Anti conformations, where there can only be Anti conformation. Backbone is negativity charges by phosphates and allow nucleotides to be held together. The strands are held together through hydrogen bonds. There are major and minor grooves (major groove contains 10 bases per turn).

Question 8

Are nucleotides hydrophobic or hydrophilic?

Answer 8

They are hydrophobic because the ring confirmation make them non polar, so it can interact with polar molecules.

Question 9

What is the UV absorption of nucleotides?

Answer 9

Nucleotides absorb UV light around 250-270 nm.