DNA Structure

Question 1

DNA is comprised of three main parts. What are they?

Answer 1

5C sugar (deoxyribose), nitrogen base (A, C, T, G), and phosphate.

Together they form a nucleotide.

Question 2

Draw a simplified and complex version of a nucleotide molecule

Answer 2

Circle, pentagon, rectangle

Phosphate - 5’C (phosphodiester bond), 1’C - nitrogenous base (N-glycosidic linkage)

Question 3

Draw a deoxyribose sugar molecule

Question 4

Draw a phosphate group

Question 5

Describe the bonds in a nucleotide

Answer 5

The 1’C of a 5C sugar is bonded to a nitrogen base by an N-glycosidic linkage.

The 5’C of the 5C sugar is bonded to a phosphate group by a phosphodiester bond.

Question 6

Draw a four nucleotide stretch of DNA

Answer 6

5’ to 3’: P - 5’, 1’ - nitrogen base, 3’ - P … 3’ - OH
3’ to 5’: HO - 3’, 1’- nitrogen base, 5’ to P … 5’ - P