Nucleotides and Nucleic Acids

Question 1

What are the electrostatic forces

Answer 1

Non covalent (ionic, Hbonds, VDW)

Question 2

How do purines name’s change when incorporated into a nucleoside

Answer 2

Adenine –> Adenosine

Guanine –> Guanosine

Question 3

How do pyrimidines name’s change when incorporated into a nucleoside

Answer 3

Uracil –> uridine
Thymine –> thymidine
Cytosine –> cytidine

Question 4

Where do bases attach in pyrimidines vs purines

Answer 4

Pyrimidines = N1
Purines = N9

Question 5

What are nucleic acids

Answer 5

Polymers of nucleotides linked by 3’–5’ phosphodiester bonds

Question 6

How do you distinguish between RNA and DNA backbone

Answer 6

RNA has Uracil instead of thymine and free 2’ OH group

Question 7

What is the approximate abs260/abs280 of pure DNA

Answer 7

1.8 –> 1.95 (abs decrease by approx 50% at 280nm)

Question 8

What stabilizes B-form DNA secondary structure?

Answer 8

Base stacking interactions

Question 9

Do free nucleotides have a higher absorbance at 260nm than ssDNA and dsDNA

Answer 9

Yes

Question 10

What kind of base pairing is in DNA vs RNA

Answer 10

RNA = intrastrand
DNA = intra + interstrand