Unit 1: DNA & RNA Structure

Question 1

What is 1 nucleotide made out of?

Answer 1

Phosphate group, Pentose, Heretrocyclic base

Question 2

What is a pentose made of?

Answer 2

Five carbons, labeled 1’ to 5’

Question 3

What are the 2 types of heterocyclic bases? What does each contain?

Answer 3

“Pure As Gold”
Purines: Adenine & Guanine
“CUT the Py”
Pyrimidines: Cytosine, Thymine, Uracil

Question 4

Which nucleotide is this?

Answer 4

Adenine

Question 5

Which nucleotide is this?

Answer 5

Guanine

Question 6

Which nucleotide is this?

Answer 6

Cytosine

Question 7

Which nucleotide is this?

Answer 7

Uracil

Question 8

Which nucleotide is this?

Answer 8

Thymine

Question 9

What forms the glycosidic bond between a base and a pentose?

Answer 9

N9 of purines or N1 of pyrimidines with C1’ of pentose

Question 10

What forms the phosphodiester bond?

Answer 10

C3’ of one nucleotide to the C5’ of another nucleotide

Question 11

What creates the 2 strands of DNA?

Answer 11

Hydrogen bonds between A&T and G&C

Question 12

What is a palindrome?

Answer 12

Self complementary pieces of DNA that create hairpins

Question 13

What are the differences in DNA and RNA structure?

Answer 13

RNA has U instead of T, and has an OH on the 2’C

Question 14

Why do we want RNA to be unstable?

Answer 14

Allows it to be dynamic and respond to fast changes in gene expression

Question 15

What are the different types of helixes?

Answer 15

B-form: DNA, bases more in the middle & stack almost horizontally
A-form: RNA, bases on the side & stack more vertically

Question 16

What are the chemical transformations that take place in nucleic acids?

Answer 16

Uncatalyzed: Uracil in DNA recognized and repaired
Catalyzed: methylation

Question 17

What is denaturation of DNA?

Answer 17

(melting) -> disruption of H-bonds between paired bases

Question 18

What is the Melting Temperature (Tm)? What does it depend on?

Answer 18

Temperature at which half of DNA is denatured. Depends on number of H-bonds and DNA length

Question 19

Which base pair has more hydrogen bonds?

Answer 19

C-G = 3
A-T = 2

Question 20

What is a southern blot used for? Northern Blot? Western Blot?

Answer 20

Southern: DNA
Northern: RNA
Western: Proteins

Question 21

What are the steps of PCR?

Answer 21

Denaturation, Annealing, Extension