Topic 2, Lecture 1 Flashcards

1
Q

sWhat accounted for the different between a neuron and liver cell?

A

the function of the cells come from the structure of the protein. later we learned that TF’s can alter the liver to a neuron by just 3 MASTOR REGULATORS ( transcription factors)

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2
Q

What were the differences in the protein expression of two tissues?

A

each tissue has its own genome
and all tissues have the same genome but different mechanism (time- specific regulation)

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3
Q

Where does regulation happen?

A

at the transcription level

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4
Q

Remember the examples of the dolly and bonnie

A

due to genomic equivalence this proves that all cells have the same genome needed to control proteins (transcribed and then made)

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5
Q

What are the important specific protein structure regulation thingys?

A

tissue-specific
gene-specific
Time-specific

BUT MOST IMPORTANTLY
right protein
right time
right amount

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6
Q

be able to draw out drawing of the gene and +1 site with appropriate labels to help with concepts

A

DRAW THAT DUDE

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7
Q

Central Dogma

A

flow of genetic information from DNA to RNA to protein

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8
Q

Regulation at transcription or at translation level?

A

it is more efficient to regulate at transcription because it is easier and it saves energy

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9
Q

what makes DNA an acid?

A

phosphodiester bonds (how we regulate gene transcription)
backbone is a (-) charge

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10
Q

how many genes encode, how many proteins?

A

30,000 genes, 24,000 proteins

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11
Q

what is the complete nucleotide of human genome

A

3.2x10^9 billion

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12
Q

how many nucleotide pairs are in chromosome 22

A

48 million

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13
Q

DNA laid end to end is what?

A

2 meters

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14
Q

Nucleus is what diameter

A

6um

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15
Q

A protein encoding gene is every

A

130 meters

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16
Q

an average gene would extend

A

30 meters

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17
Q

Chromatin is what?

A

fibrous, nucleoproteins (DNA/Proteins) complexed within the nucleus

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18
Q

what does chromatin consists of?

A

DNA, histones, Nucleosomes, and non-histone proteins.
It is about 1/3 DNA and 2/3 proteins

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19
Q

Chromosomes are

A

linear, double-stranded DNA molecule and associated proteins it is highly condensed DNA

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20
Q

DNA double helix is decondensed proteins that form a what? but it is also only transcribed at what length? (beads on a string)

A

chromosome scaffold
11mm

21
Q

Chromosomes are formed from? but the way they look is determined by what?

A

formed from chromatin
look is determined by stage of cell cycle

22
Q

What is the typical structure of the histone fold?

A

H2A and H2B form dimer through an intersection called a handshake

23
Q

How many turns does the DNA helix make around the histone octomer?

A

1.7 tight turns

24
Q

Histone tails are

A

tails that stick out (8) on n- terminus
11-37 AA on n-terminus that extend from nucleosome

25
Q

Tails can under go what?

A

MODIFICATIONS

26
Q

Linker Histone is

A

the linker that keeps the tails close to the histone core

27
Q

what are the tails doing?

A

help like one nucleosome to next nucleosome
beings everything together (paper clip holding paper)

28
Q

heterochromatin

A

highly condensed regions of chromosome that stain darkly
transcriptionally inactive

29
Q

heterochromatin undergoes two stages

A

facultative
constitutive

30
Q

facultative

A

decondensed and go back and forth from hetero to euchromatin

31
Q

constitutive

A

stays condensed as hetero and rarely if ever transcribed

32
Q

euchromatin

A

light regions
less condensed regions of chromatin
site of gene transcription

33
Q

If modifying histones to induce heterochromatin what formation must be tightly packed?

A

histone tails - hetero
specific proteins lock heterochromatin in place, not just a matter of DNA being tightly packed but keeping it condensed to bind to proteins.

34
Q

What percent open-active chromatin in the cell (housekeeping gene encodes)?

A

20%

35
Q

what falls under constitutive heterochromatin?

A

centromere and telomere

36
Q

What do the modifications of the tails do to histones?

A

how tails pack
hetero- tightly condensed
euchromatin- spread out (transcribed)

37
Q

But what’s the story behind modifications?

A

histone modification, morphology of nucleus, and degree of transcription
are all apart of the story

38
Q

Lampbrush

A

the dark area is the scaffolding, fuzzy loops

39
Q

Lambrush loops contain how many nucleotide pairs?

A

50,000 to 200,000 nucleotide pairs

40
Q

the extended loops are

A

the active sites of transcription at 11nm

41
Q

the tight loops are

A

30nm

42
Q

nuclear neighborhoods

A

subcompartments that can accelerate complete sets of chemical reactions
locked on the loop of the 30nm fiber

MOLECULAR GLUE THAT KEEPS WHAT NEEDS TO BE HERE IN PLACE

43
Q

Why have a gene that would not be transcribed in a nuclear neighborhood? (active or passive approach)

A

active or passive approach to regulating gene transcription

passive would NOT DO IT
some want ACTIVE

cannot transcribe a gene, so lock it in NUCLEAR NEIGHBORHOODS with heterochromatin

REMEMBER MOLECULAR GLUE

44
Q

histones include how many nucleosome pairs of DNA

A

200
50 in between and 150 wrapped

45
Q

typical diploid human cell contains how many nucleosomes

A

30 million

46
Q

small basic portions of histones

A

H1 H2A H2B H3 H4

47
Q

how many bonds are btw dna and histone core? and how many of these form between the AA and phosphodiester backbone

A

142 and 1/2 of these form btw AA and phosphodiester backbone

48
Q

how many copies of each histone per cell in humans

A

60 million