CH 6

Question 1

In Eukaryotes, DNA is stored in the

Answer 1

nucleus

Question 2

Chromatin

Answer 2

Complex of DNA and proteins, keeps it from getting tangled

Question 3

Chromosome

Answer 3

Chromatin stored in condensed shapes

Question 4

The ends of Eurkaryotic chromosomes are…

Answer 4

Telomeres - caps that protect them
TTAGGG repeats

Question 5

Replication origin

Answer 5

where replication begins

Question 6

Centromere

Answer 6

area where microtubules attach during cell division

Question 7

Bacterial Chromosomes

Answer 7

-Circular
-located in nucleoid
-single replication origin

Question 8

Plasmids

Answer 8

-smaller circular pieces of DNA
-can encode useful traits like anti-biotic
resistance

*distinct from chromosomal DNA

Question 9

What holds bases in DNA together

Answer 9

hydrogen bonds

Question 10

Base Pair

Answer 10

set of two complimentary nucleotide bases

-purines (A, G) pair with pyrimidines (C, T, U)

Question 11

Nucleotide composition

Answer 11

One phosphate group, Nitrogen base, 5 Carbon sugar

Question 12

Nucleoside di and triphosphates do…

Answer 12

carry energy in their bonds

Question 13

di and triphosphates combine w other groups to form

Answer 13

coenzymes

can also be used as small intracellular signaling molecules

Question 14

key difference between RNA and DNA

Answer 14

RNA has an extra OH on 5C sugar

Question 15

what bonds form nucleic acid polymers

Answer 15

phosphodiester bonds

Question 16

synthesis of DNA or RNA is driven by

Answer 16

ATP hydroylsis

Question 17

Specific sequences where initiator proteins bind…

Answer 17

break hydrogen bonds between strands

Question 18

DNA polymerase function

Answer 18

synthesizes DNA using parent strand as a template

Question 19

Growth direction

Answer 19

5’ –> 3’

Question 20

what attaches a base pair

Answer 20

nucleoside triphosphate pairs with base in the template strand, DNA polymerase catalyzes the covalent linkage

Question 21

DNA Primers are made of

Answer 21

short lengths of RNA

Question 22

Primer

Answer 22

short sequence of nucleotides

Question 23

Primase

Answer 23

RNA polymerase that binds to DNA in replication fork to synthesize a primer

Question 24

Sequence of replication

Answer 24

Primase makes RNA primer

DNA poly binds to RNA/DNA double strand

DNA poly extends RNA primer w/ DNA

Question 25

Nicks are sealed by...

Answer 25

Ligase

Question 26

DNA polymerase is self correcting...

Answer 26

Proofreading allows a mispaired nucleotide to be removed

Question 27

For proofreading to occur, DNA must...

Answer 27

be copied in 5' - 3' direction because there is not high energy bonds on the 3' end

Question 28

Hydrolysis of what drives the overall reaction of polynucleotide synthesis

Answer 28

pyrophosphate - hydrolysis is highly favorable

Question 29

Clamp Loader function

Answer 29

allows the same DNA poly to polymerize all of the Okazaki fragments uses ATP to lock sliding clamp to DNA

Question 30

DNA helicase

Answer 30

uses energy of ATP hydrolysis to pry apart DNA double helix ahead of the fork

Question 31

Single-strand DNA binding protein

Answer 31

Binds to exposed DNA strands preventing base pairs from reforming

Question 32

Topoisomerase

Answer 32

Produces transient breaks in one strand of double helix to relive tension caused by unwind of DNA

Question 33

Sliding Clamp

Answer 33

Keeps DNA polymerase attached to template allowing the enzyme to slide

Question 34

Ligase

Answer 34

uses ATP hydrolysis to join Okazaki fragments made on lagging strand

Question 35

DNA relives torsional stress by...

Answer 35

Supercoiling with topoisomerase -DNA freely rotates around broken single bond -breaks backbone

Question 36

Telomerase

Answer 36

replicates end of eukaryotic chromosomes adds bases 5' to 3' on the lagging TEMPLATE strand *allows replication proteins to replicate lagging strand without it shrinking with each division

Question 37

3 steps of DNA repair

Answer 37

1) excision Damage is recognized and cut out by one of a series of nucleases 2) Resynthesis orginal sequence is restored by REPAIR DNA POLYMERASE 3)Ligation DNA Ligase seal the break left in the backbone

Question 38

DNA mismatch repair system

Answer 38

removes replication errors that escape proofreading

Question 39

Double strand DNA breaks require different strategy...

Answer 39

Non-Homologous end joining

Question 40

Homologous recombination

Answer 40

preferred restoration of sequence -Requires shortly after replication w homologous DNA copy nearby -no loss of nucleotides at repair site -complimentary base pairing

Question 41

Non-Homologous end joining

Answer 41

loss of nucleotides at repair site "quick and dirty"

Question 42

One single nucleotide change can cause

Answer 42

disease like sickle cell

Question 43

Homologous recombination is found in virtually all cells on Earth

Answer 43

Shared by many organisms because they are so critical