Chromatin, Operons, & DNA Replication Flashcards

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1
Q

progeria: interruption with

A

nuclear lamina

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2
Q

we know about proteins due to the … that occur with them

A

proteins

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3
Q

heterochromatin is a … version of chromatin

A

densely packed

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4
Q

heterochromatin leads to … of genes by inhibiting … at these locations, prevents access of … necessary for transcription

A

inactivation; transcription; enzymes

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5
Q

euchromatin are … chromatin –> … occurs in these regions

A

loosely packed; transcription

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6
Q

chromatin consists of … and .., namely DNA wrapped around … to form … that are held together either as “… on a …” (…) or as a structure of … in width (…)

A

DNA; proteins; histones; nucleosomes; beads; string; euchromatin; 30 nm; heterochromatin

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7
Q

about .. base pairs of DNA wrap around complexes of … histones, composed of … of each of the four different types: …, …., …, …

A

150; 8; two; H2A; H2B; H3; H4

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8
Q

Nucleosomes are joined together by way of

A

linker DNA

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9
Q

chromosomes are formed during …, when the cell is undergoing …

A

mitosis; cellular division

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10
Q

in …, chromatin begin to condense, which is when the chromosome becomes visible. During …, in which the cell is not dividing, the chromatin is in its … state, allowing for … to occur

A

prophase; interphase; least condensed; transcription

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11
Q

modification of the … regulates gene expression

A

histone tail

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12
Q

…. of the histone (addition of an … group) … the coils

…. (addition of a … group) … the coils

A

acetylation; acetyl; loosens; methylation; methyl; tightens

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13
Q

…. reduces the space needed for DNA within the cell. It reduces the … on the molecule by allowing it to … around itself. It can also regulate …

A

supercoiling; helical stress; twist; transcription

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14
Q

positive supercoiling: DNA is … –> …-handed twisting of the DNA
negative supercoiling: DNA is … (most DNA like this) –> …-handed twisting of the DNA, makes it easier to … the DNA strands

A

overwound; left; underwound; right; separate

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15
Q

epigenome refers to the … that regulate gene expression (e.g. …, …, etc.)
can be influenced by … factors

A

chemical compounds/modifications; DNA methylation; histone methylation; environmental

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16
Q

operon –> grouping of

A

genes

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17
Q

prokaryotes have to control which genes will be expressed, based on the … that they are in

A

environment

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18
Q

E.coli cells in environment with glucose, maltose and lactose would select … first in their metabolic genes, breaking it down by way of … (which involves … enzymes, leading to a net yield of … ATP). They would then select either maltose or lactose, building the enzymes responsible for breaking them down.

A

glucose; glycolysis; 9; 2

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19
Q

repressor proteins sit on top of …. and block …

A

gene segment; transcription

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20
Q

glucose is the …, … energy source

A

preferred; universal

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21
Q

operons are named after their … (what they act on)

A

substrate

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22
Q

lac operon –> used for …. –> …, inducer is … (…)

A

lactose; inducible; lactose; allolactose

23
Q

permease enzyme allows lactose to …, and beta galactosidase … to glucose and galactose

A

enter the cell; hydrolyzes lactose

24
Q

trp operon is used for … (an ….) –> …, tryptophan is the …

A

tryptophan; amino acid; repressible; repressor

25
Q

prokaryotes make tryptophan and don’t need to … it BUT if it is in solution/agar that they are plated on, they don’t make it so that they don’t waste …, …, etc –> gene segment for tryptophan would be …

A

consume it; energy; resources; turned off

26
Q

operons allow for prokaryotes to

A

regulate gene expression

27
Q

(differences between trp and lac operon) trp operon leads to an … pathway whereas lac operon leads to a … pathway

A

anabolic; catabolic

28
Q

(differences between trp and lac operon) lac is … whereas trp is ….

A

inducible; repressible

29
Q

(differences between trp and lac operon) lac is controlled by the abundance of the … whereas trp is not dependent on the conditions of the …, although it can be repressed by these conditions

A

substrate; environment

30
Q

(differences between trp and lac operon) trp is deactivated by the presence of … whereas lac is activated by the presence of …

A

tryptophan; lactose

31
Q

(differences between trp and lac operon) the trp repressor is …, whereas lac is … Also, the trp repressor cannot bind to the …, but the lac repressor can

A

inactive; active; operator region

32
Q

generating permeases leads to more …, more lactose in less …

A

efficiency; time

33
Q

interaction between … and … regulates gene expression

A

repressor; inducer

34
Q
regions of operon (gene segments): 
... 
... 
... 
...
A

operator; repressor; promoter; regulatory region

35
Q

repressor sits on top of the

A

operator

36
Q

the lactose repressor … after the binding of lactose, preventing the repressor– the … gene — from binding to the …. This allows … to attach to the …, which has been exposed by the binding of a … complex to a … binding site such that the … can fully bind to it. Transcription follows, by which enzymes necessary for lactose metabolism are produced

A

changes shape; regulatory; operator; RNA polymerase; promoter; CAP; CAP; RNA polymerase;

37
Q

DNA replication occurs in three steps: …, …., and …

A

unwinding; complementary base pairing; joining

38
Q

unwinding is the process by which the parental strands, also known as the … strands, are separated by way of a …

A

template; helicase enzyme

39
Q

the point at which helicase begins separating the strands is known as the … At this point, helicase begins breaking the … between the .., forming two … – the two exposed strands of DNA that will undergo base pairing–which constitute a … that will grow as replication proceeds

A

origin of replication; hydrogen bonds; base pairs; replication forks; replication bubble

40
Q

… stabilize the separated strands to ensure that the hydrogen bonds will not reform between the base pairs

A

single stranded binding proteins

41
Q

before complementary base pairing can occur, …, an …., generates an … at the origin of replication because DNA polymerase can only attach new nucleotides to an … of nucleotides

A

primase; RNA polymerase; RNA primer; existing strand

42
Q

Free nucleotides that were produced and stored in the cell prior to replication are then paired with nucleotides on the parental strands by way of …

A

DNA polymerase

43
Q

the parental strands that are part of the fork ran … to one another, and the new strands being formed must also be … to the template strands

A

antiparallel; antiparallel

44
Q

replication must occur in the … to .. direction, as nucleotides can only be added to the … group at the … end of the chain. This requirement leads to the formation of the … and … strands

A

5’; 3’; -OH; 3’; leading; lagging

45
Q

the parental strand that is in the 3’ to 5’ direction is termed the … strand, and the parental strand that is in the 5’ to 3’ direction is termed the … strand

A

leading; lagging

46
Q

replication in the leading strand occurs in the … direction that the fork is moving, while replication in the lagging strand occurs in the … direction that the fork is moving.

A

same; opposite

47
Q

the lagging strand is replicated in segments called …. due to the fact that DNA polymerase must stop and restart due to the … of synthesis

A

Okazaki fragments; direction

48
Q

the strands are … to ensure that no mistakes are made and … are removed by DNA polymerase and replaced with …

A

proofread; RNA primers; DNA nucelotides

49
Q

… then joins the fragments to form the … molecules that are comprised of one parental and one new strand

A

DNA ligase; daughter DNA

50
Q

Both prokaryotes and eukaryotes exhibit … replication, but some prokaryotes can exhibit … replication

A

bidirectional; unidirectional

51
Q

in prokaryotes, there is …. point of origin, but in eukaryotes replication occurs at many different ….

A

only one; replication bubbles

52
Q

… is the site of replication in prokaryotes. … is the site of replication in eukaryotes

A

cytoplasm; the nucleus

53
Q

eukaryotes have … types of DNA polymerase, whereas prokaryotes have … types of DNA polymerases, but eukaryotic polymerases work … than prokaryotic polymerases

A

4; 2; slower

54
Q

prokaryotes have only … site of termination, while eukaryotes have .. than one site of termination. Eukaryotes also face the problem of having some DNA that does not get …, which is solved by the presence of …–non-coding, repetitive sequences of DNA

A

one; more than one; replicated; telomeres