Nucleic Acid Structure Lecture 3 Ford

Question 1

What makes up a nucleotide?

Answer 1

Phosphate group, sugar, and a base

Question 2

What makes up a nucleoside?

Answer 2

Sugar and a base

Question 3

What is the difference in DNA and RNA structure?

Answer 3

DNA uses deoxyribose, which lacks an -OH group at the 2’-C and RNA uses ribose, which has an -OH group at the 2’-C

Question 4

DNA vs RNA

Answer 4

DNA: Used for storage, has 2 strands, deoxyribose sugar, uses pyrimidines C and T, uses purines A and G

RNA: Used for transport, catalysis, and regulation, has 1 strand, ribose sugar, uses pyrimidines C and U, uses purines A and G

Question 5

What is special about in vitro oligonucleotide synthesis?

Answer 5

Synthesis proceeds in the 3’ to 5’ direction

Question 6

B DNA

Answer 6

Physiologically relevant conformation

Question 7

Where is A DNA usually seen?

Answer 7

RNA

Question 8

3 Non-Traditional Structures

Answer 8

Hairpins/Cruciforms, triplexes, and quadruplexes

Question 9

Hairpins and Cruciforms

Answer 9

Require palindromic sequence (inverted repeated); created by superhelical strain

Question 10

Triplexes

Answer 10

May or may not occur in nature; requires a homopurine-homopurine duplex; uses Hoogsteen hydrogen bonds

Question 11

Quadruplexes

Answer 11

Guanines only; occurs at telomeres and some promoters

Question 12

Melting Temperature

Answer 12

Temperature at which delta G is equal to 0 (DNA goes from DS to SS or when 1/2 of sample is denatured (SS)

Question 13

How does DNA go from 2 strands to 1 strand?

Answer 13

Like a zipper