Drawing Nucleic Acids and Backbone

Question 1

What is the structure of a nucleotide?

Answer 1

Base, pentose sugar (nucleoside), and one or more phosphates attached on the 5’ C of the pentose sugar

Question 2

What is the structure of a nucleoside?

Answer 2

Base and pentose sugar, which are attached at the 1’ C of the pentose sugar in a beta-glycosidic bond

Question 3

What is the general structure of purines?

Answer 3

Double ringed
4 double bonds total
N in rings at 1, 3, 7, and 9

Question 4

Which position does a glycosidic bond form with purines?

Answer 4

At the 9 N

Question 5

Which position does a glycosidic bond form with pyrimidines?

Answer 5

At the 1 N

Question 6

What is the general structure of pyrimidines?

Answer 6

Single ringed
3 double bonds total
N in rings at 1 and 3 positions

Question 7

Which bases are purines?

Answer 7

Adenine and Guanine

AnGels are PURe

Question 8

Which bases are pyrimidines?

Answer 8

Cytosine, Uracil (RNA only), Thymine (DNA only)

Question 9

Draw Adenine

Answer 9

NH2 on 6

Question 10

Draw Guanine

Answer 10

NH at 1

H2N on 2

Question 11

Draw Cytosine

Answer 11

NH at 1
=O on 2
NH2 on 4

Question 12

Draw Uracil

Answer 12

NH at 1
=O on 2 and 4
NH at 3

Question 13

Draw Thymine

Answer 13

N at 1
=O on 2 and 4
NH at 3
CH3 on 5

Question 14

Draw an example of DNA backbone

Answer 14

Sugars are linked via 3’ OH and 5’ OH through phosphate
Bases are connected at 2’ C of sugar
3’ to 5’ phosphodiester linkage
Directionality overall: 5’ to 3’