Nucleotides & Nucleic Acids

Question 1

What are the nucleobases?

5

Answer 1

A, G, C, T, U

Question 2

How are nucleobases “typically” paired?

Answer 2

A-T or A-U
G-C

Question 3

How do carbohydrates of DNA and RNA differ?

Answer 3

DNA contains deoxyribose which has an additional OH group on C2.

RNA has a hydrogen instead at this position.

Question 4

What components do nucleotides consist of?

Answer 4

A sugar (ribose or deoxyribose), a nitrogen-containing base and a phosphate backbone.

Question 5

How are nucleotides bound together?

Answer 5

Phosphodiester bonds between the 3’ hydroxyl of one sugar and the 5’ phosphate group of the next.

Question 6

What are the main structural differences of RNA and DNA?

3

Answer 6

• Deoxyribose vs Ribose as the sugar
• DNA is double-stranded, RNA is mostly single-stranded
• DNA has thymine as a nucleobase vs RNA with uracil

Question 7

Which type of DNA is considered to have a “normal” structure?

Answer 7

B-DNA

Question 8

Purines:

Answer 8

Adenine, Guanine

Question 9

Pyramidines:

Answer 9

Cytosine, Uracil, Thymine

Question 10

The N-termini has a/n … group

Answer 10

amine

Question 11

The C-termini has a/n … group

Answer 11

carboxylic acid

Question 12

Which type of pairing is strongest and why?

Answer 12

C-G, pairing contains 3 hydrogen bonds

Question 13

What does a chromosome consist of?

Answer 13

DNA double-helix is wound around histones, which is wound to form chromatin fibers. These are further wound up to form chromosomes.