Chap 2

Question 1

Nucleoside

Answer 1

Base, sugar, but no phosphate

Question 2

RNA 2’ carbon

Answer 2

OH

Question 3

Length of RNA is measured by

Answer 3

Nucleotide number

Question 4

two strands/secondary structure is stabilized by

Answer 4

Base pairs h bonding (of backbone) and base stacking

Question 5

Base stacking

Answer 5

Bases stack like stairs to keep together, keeps water out (hydrophobic)

Question 6

Major groves

Answer 6

Wide grove- where proteins can interact with DNA the most

Question 7

Minor grove

Answer 7

Narrower grove, interacted with less

Question 8

B form/ watson crick form

Answer 8

Standard, right handed, 10.5 bp/turn, high humidity, low salt, 5’ to 3’, major groove is deep and minor grove is shallow and broad

Question 9

A form

Answer 9

Right handed, 11bp/turn, low humidity, high salt, associated with RNA, major and minor grove is moderate,

Question 10

Z DNA

Answer 10

Left handed, “single grove”, 12 bp/turn, high MgCl or ethanol and methylated cytosine, linked to certain diseases, can occur in vivo

Question 11

Nucleic acid

Answer 11

polymers made up of nucleotides

Question 12

Nucleotide

Answer 12

Nucleic acid subunits made of a sugar, phosphate, and nitrogenous base

Question 13

Deoxyribose

Answer 13

H on 2’ C

Question 14

Chargaffs rules

Answer 14

GC content varies across species, but within the species, it is the same

Question 15

DNA is held together by

Answer 15

Covalent bonds (phosphodiester bonds) and h bonds (bases bonds)

Question 16

Hyperchromicity

Answer 16

As dna melts, its absorption of UV increases

Question 17

Melting temperature

Answer 17

The temp at which half the bases in the dsDNA sample has melted

Question 18

Hybridization

Answer 18

Complementary base pairs from two different sources

Question 19

Denaturation temp effected by

Answer 19

GC content, salt concentration (higher salt, higher temp), ph,

Question 20

Reanneling rate effected by

Answer 20

Concentration of DNA, repeativity,

Question 21

Cop curve ?

Answer 21

Show how long dna will reanneal

Question 22

Slipped structure

Answer 22

(DNA 2nd) in short tandem repeats, can result in deletions and insertions

Question 23

Cruciforms

Answer 23

At palindromes or inverted repeats, a loop is forms, leads to genetic instability,

Question 24

Triple helices

Answer 24

(DNA 2nd) Happens in mirror repeats, extra strand pops up in major grove, leaves one DNA single stranded,

Question 25

Hoogsteen base pairs

Answer 25

3 base pairs bonding, associated with friedreich ataxia (loss of muscular coordination and heart enlargement), alt ways to Watson crick bond

Question 26

G quadruplex

Answer 26

(DNA2) 4 stranded in a stretch of tandem guanine, for gene regulation, found in telomeres and promoters

Question 27

Super coiling is done to

Answer 27

Conserve space, put energy into DNA molecule (negative), unwinds DNA for replication, transcription and recombination (negative)

Question 28

Linking number

Answer 28

Number of times two hydrogen bonded strands cross each other

Question 29

Writhes

Answer 29

Number of time DNA helix is coiled about itself

Question 30

Linking number formula

Answer 30

Twist plus writhes

Question 31

Partial denaturation

Answer 31

Done to relieve strained supercoiling

Question 32

Why does positive supercoiling occur

Answer 32

DNA replication and transcription (ahead of fork),

Question 33

Topoisomerases

Answer 33

Release supercoiling

Question 34

primary structure of DNA

Answer 34

nucleic acid and nucleotides, held by phosodiester bonds

Question 35

fidelity of DNA replication

Answer 35

proofreading DNA repair mechanisms and correct mistakes

Question 36

dsDNA has a - core

Answer 36

hydrophobic

Question 37

negative supercoiling

Answer 37

saves space, energy into DNA molecule, almost all DNA in pro and euk is negatively supercoiled, under wound

Question 38

DNA tertiary structure

Answer 38

supercoiling

Question 39

RNP

Answer 39

Catalyze replication, transcription, ribosome, the enzyme telomerase, vault ribonucleoproteins, RNase