Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

Biochemistry 2065 > DNA Replication and Repair > Flashcards

DNA Replication and Repair Flashcards

(78 cards)

Start Studying
1
Q

genome

A

all the DNA in an organism, including genes and non coding parts

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

plasmids

A

accessory replicating DNA molecules

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

chromosome

A

a dna molecule with part or all of the genetic material of an organism

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

T/F a chromosome contains all the essential genetic information for life

A

true

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

T/F chromosomes are usually linear in humans and circular in bacteria

A

t

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

T/f plasmids are smaller than chromosomes

A

true

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

genes

A

parts of DNA that are transcribed

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

T/F virus genomes can be RNA or DNA

A

t

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

____ are the simplest cellular life forms, can be free-living or obligate endosymbionts of other host cells

A

prokaryotes (arcaea and bacteria)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

prokaryotes genomes typically range from __ to ___ genes

A

400 to 9 000

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

T/F most genes in prokaryotes are found in a single circular chromosome

A

true

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

t/f some bacteria have multiple chromosomes and linear chromosomes

A

true

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

eukaryotic dna is wrapped around proteins called __

A

histones

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

dna wrapped around a histone is collectively called a __

A

nucleosome

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

the formation of nucleosomes contributes to the ___ of dna

A

packing

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

nucleosomes arrange into helical stacks called __

A

chromatin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

folding of chromatin creates __

A

chromosomes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

t/f chromosomes are the highest condensed structures

A

t

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

structure of chromatin during interphase and reason for this structure

A

loose; allowing DNA polymerase to get at the genes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

during which cell stage is dna copied in preparation for mitosis?

A

interphase

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

in which stage of the cell cycle do chromosomes condense from chromatin? why?

A

metaphase ; to ease the separation of daughter cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

what % of the human genome is coding?

A

1.5%

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

protein coding DNA in humans is __%

A

2

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

how many exons/introns in bacterial genes

A

one exon, no introns

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
how many exons/introns in eukaryotic genes
multiple axons and introns
26
introns nad exons are ___ with a gene
nucleotide sequences
27
introns are removed by ___
RNA splicing
28
exons are covalently bonding to each other to make __
mRNA
29
DNA replication is semi-conservative, meaning :
each daughter cell gets a copy of DNA that is half from the parent and half newly made
30
the new DNA is assembled directly on a ___
pre-existing DNA template
31
role of helicase:
separates the dna strands making a fork with 2 template strands
32
role of single strand binding proteins (ssb)
stabilize the strands and prevent annealing
33
role of primase
creates RNA primers, required to start replication
34
role of DNA polymerase iii
binds at primer, builds the complementary strand from there
35
role of DNA polymerase 1
removes primers as dns polymerase 3 approaches it
36
dna polymerase 1 is especially important in the __ strand
lagging
37
role of dna ligase
joins Okazaki fragments by joining phosphodiester bonds between adjacent nucleotides
38
what enzymes unwinds dsdna in front of DNA polymerase?
helicase
39
helicase is made of how many subunits?
3 different, 6 total
40
t/f helicase is a hexamer
t
41
SSbs are removed when ___ approaches
polymerase 3
42
what is an RNA primer?
short RNA segment that allows the polymerase to start replication
43
dna polymerase 3 catalyzes the step-by-step addition of __ to a dna strand
deoxyribonucleotide
44
DNA polymerase makes dna in the ___ direction
5' --> 3'
45
DNA polymerase requires what 4 things?
1. a template strand of dna 2. a primer 3. precursors 4. mg 2+ cofactors
46
primers initiate __
transcription
47
what are precursors?
the building blocks of the dna product: the deoxyribonucleotide triphosphate
48
DNA + dNTP =
dna + pyrophospate ion
49
the strand elongation reaction catalyzed by polymerases is a nucleophilic attack by the ___ end of the growing strand to the ___ of dNTP
3'OH ; innermost phosphorus atom
50
the 2 Mg increase the ___and help the position of __ in the active site
nucleophilicity of attacking OH; phosphates
51
after attack by OH, a ___ bridge is formed and ___ is released
phosphodiester; pyrophosphate
52
what happens to the released pyrophosphate that drives the polymerization forward?
hydrolyzed into 2 orthophosphates
53
the basic structure of DNA polymerases resembles what anatomical structure/
an open right hand
54
the "palm" of a dna polymerases contains ___
DNA, catalytically essential amino acids
55
the "fingers" of dna polymerases are essential for __
nucleotide recognition and binding
56
the "thumb" of dna polymerases are important to __
binding of the DNA substrate (dNTPs)
57
the upper strand is the ___ strand; replication is ___
leading ; continuous
58
the lower strand is the ___ strand ; replication is ___
lagging; discontinuous
59
what part of DNA polymerase 1 removes the RNA primer?
the exonuclease
60
dna polymerase 3 disengages when ___
the 2 okazaki fragments meet
61
role of DNA ligase
joins the Okazaki fragments
62
ligase catalyzes the formation of a phosphodiester bond between ___ at the end of one dna chain and the ___ at the end of the other
3'OH group; 5' phosphoryl
63
DNA damage can be thought of in what 2 ways?
1. errors during replication | 2. chemical changes to the nucleotides after replication
64
what is non-watson-crick base pairing?
when dna incorporates the wrong nucleotide
65
what is the effect of non-watson crick base pairing on the dna double helix?
local distortion
66
what does it mean if a non-watson crick base pairing is mutagenic?
results in permanent changes in DNA sequence
67
when a double helix containing a non-watson-crick base pairing is replicated, the 2 daughter cells will have __ sequences because __
different; the mismatched base is likely to pair with its Watson crick partner
68
the ___ subunit of DNA polymerase 3 core has ___ activity that can remove an incorrect nucleotide
epsilon; exonuclease
69
exonuclease
enzyme that removes successive nucleotides from the end of a polynucleotide molecule
70
alfatoxin
hydrocarbon molecule and a toxin produced by molds that grow on food, like peanuts
71
in the cell, aflatoxin is converted to an activated form that can modify ___ in DNA
guanine residues
72
aflatoxin frequently leads to the conversion of a G-C into a ___ mutation
A-T
73
mis-matches in dna can be repaired by a process called __
mis-match repair
74
2 enzymes __ and ___ can recruit an enzyme __ that cuts the single strand near the mis-match. A __ then cuts away the single strand with the mis-match
MutS and MutL; MutH; exonuclease
75
electromagnetic radiation, such as UV light induces ___ between adjacent pyrimidines along one strand of DNA
cross-links
76
pyrimidine dimers are the primary cause of ___ in humans
melanomas
77
the ____ repair system can recognize and excise thymine dimers
UvrABC excinuclease
78
high fidelity in dna replication is maintained by what 3 things?
1. accuracy of DNA polymerase 2. proof-reading 3. mismatch repair

Biochemistry 2065 (19 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions