Topic 2

Question 1

Avery MacLeod

Answer 1

Transformative element = DNA

Question 2

Hershey-Case

Answer 2

bacteriophage labeled with DNA has radioactive progeny

Question 3

Mono/dinucleotides

Answer 3

redox rxn, energy transfer, intracellular signalling, biosynthetic reaction

Question 4

examples of mon/dinucleotides

Answer 4

NAD+/NADPH, ATP, GTP, cAMP

Question 5

polynucleotides

Answer 5

storage and code genetic info, as enzymes

Question 6

examples of polynucleotides

Answer 6

DNA/RNA, RNA enzymes, riboenzyme

Question 7

Nucleotides are..

Answer 7

make up nucleic acids, high energy molecules (NTP and electron carriers)

Question 8

Nucleotide composition (dAMP)

Answer 8

phosphate, nitrogen containing aromatic base, deoxyribose sugar

Question 9

Pyrimidine

Answer 9

1 ring, 2 N at 1 and 3

Question 10

Uracil

Answer 10

pyrimidine, 2 carboxyl, 2 amide, 6 H-bonds

Question 11

Thymine

Answer 11

pyrimidine, 2 carboxyl, 2 amide, 1 methyl, 6 H-bonds

Question 12

Cytosine

Answer 12

pyrimidine, 1 carboxyl, 3 amide, 6 H-bonds

Question 13

Purine

Answer 13

2 rings, N at 1, 3, 7, 9, start numbering N farthest from smaller ring

Question 14

Adenine

Answer 14

purine, 4 amide, 1 amide branch, 6 H-bonds

Question 15

Guanine

Answer 15

purine, 1 carboxyl, 1 amide branch, 8 H-bonds

Question 16

RNA bases

Answer 16

GACU

Question 17

DNA bases

Answer 17

CAGT

Question 18

Nucleoside

Answer 18

5C sugar bound to:
N1 in pyrimidine
N9 in purine

Question 19

RNA 5C sugar

Answer 19

ribose

Question 20

DNA 5C sugar

Answer 20

deoxyribose

Question 21

Naming nucleosides

Answer 21

purine ends in -osine
pyrimidine ends in -idine
ribose no prefix
deoxyribose add deoxy-

Question 22

Nucleotides

Answer 22

5C sugar connected to phosphate with phosphodiester bond

Question 23

naming nucleotides

Answer 23

ribose/deoxyribose name, 5’ mono/di/triphospahte

Question 24

Ribose

Answer 24

5C sugar, OH at C1 (up), C2 (down), C3(down), OCH2 at C4

Question 25

Deoxyribose

Answer 25

5C sugar, OH at C1 (up), H at C2 (down), C3(down), OCH2 at C4

Question 26

Phosphoester bond

Answer 26

phosphate ester, link carbons to phosphates

Question 27

Phosphodiester bond

Answer 27

2 phosphate ester bonds, links 2 different carbons

Question 28

Phosphoanhydride

Answer 28

link 2 phosphates together

Question 29

Structure of nucleic acids

Answer 29

direction 5' to 3'

Question 30

primary structure of nucleic acids

Answer 30

order of monomers in a polymer ex. 5' AGTC 3'

Question 31

Backbone

Answer 31

net charge comes from phosphate polar backbone in RNA is more polar > contains 2' OH (H-bonds)

Question 32

Phosphates attached to a single C

Answer 32

mono- di- tri-

Question 33

Phosphates attached to multiple C

Answer 33

bis- tris-

Question 34

Hydrolysis of phosohodiester

Answer 34

phosphodiesterase

Question 35

DNA is more stable than RNA because....

Answer 35

doesn't have a second OH that can spontaneously hydrolyze in alkaline (pH > 10) conditions

Question 36

how does cytosine turn into uracil

Answer 36

deanimates the 4C

Question 37

Properties of the Bases

Answer 37

- heterocyclic - aromatic - planar - poorly soluble in water - hydrophobic

Question 38

sugar phosphate backbone polar or non polar?

Answer 38

POLAR

Question 39

hyperchromicity

Answer 39

increase in absorbance | ex. when DNA or RNA denatures

Question 40

A260/A20 DNA

Answer 40

1.8-1.95

Question 41

A260/A20 protein

Answer 41

<1

Question 42

used to measure conc of nucleic acids

Answer 42

A260 and Beer Lamberts Law

Question 43

Secondary structure of DNA

Answer 43

dna forms double helix through H-bonds (non-covalent)

Question 44

Chargaff's Rule

Answer 44

A=T C=G

Question 45

DNA (B-form)

Answer 45

``` structure in aqueous environment hydrophobic core polar exterior bases excluded from H2O rib/deoxyrib exposed to H2O H bonds in base pairing ~10 bp per turn ```

Question 46

Base-stacking

Answer 46

primarily Van der Waals also hydrophobic forces anti parallel right handed twist

Question 47

DNA denaturation

Answer 47

ds to ss disruption of base stacking and H-bonds essential for transcription and translation changes in absorption

Question 48

Tm

Answer 48

midpoint of melting | characteristic of base composition and solvent conditions

Question 49

Hypochromicity

Answer 49

Low absorbance ex. ds DNA

Question 50

Renaturation

Answer 50

reformation of DNA, nucleation and zippering

Question 51

which bonds in base pairing are stronger and why?

Answer 51

GC triple bonds and more H bonds

Question 52

More GC =

Answer 52

higher Tm

Question 53

A260/280 ratio RNA

Answer 53

~2.1

Question 54

RNA secondary structure

Answer 54

H-bonded base pairs 2' OH group Helical Hydrophobic/ van der Waal

Question 55

RNA base pairing

Answer 55

intrastrand

Question 56

DNA base pairing

Answer 56

interstrand

Question 57

low salt = Tm

Answer 57

decreases, double helix destabilizes

Question 58

high salt = Tm

Answer 58

increases, stabilizes helix

Question 59

pH increases = Tm

Answer 59

decreases