Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Molecular Biology > L9 Epigenetics > Flashcards

L9 Epigenetics Flashcards

You may prefer our related Brainscape-certified flashcards:
AP® Biology flashcards Biology 101 flashcards
1
Q

Define epigenetics

What explains the different development and function of similar cells

A

mechanisms outside the direct genetic code which influence gene expression

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

How does chromatin play a role in epigenetics

A

through histone modifications, nucleosome positioning, histone variants, and DNA modification

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

What are epigenetic traits

A

stably heritable phenotypes resulting from changes in a chromosome without alterations in DNA sequence

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

What are examples of biological phenomena that are attributed to epigenetics

A

development of embryo, coat color in calico cats

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

Why are post translational modifications important for histones

A

act as signals during regulation; modifications can prevent or facilitate the recruitment of specific proteins to the chromatin

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

Why are histone tails important

Why are they are not observed in crystal structures

A

they are not ordered and interact with other nucleosomes to help compact the DNA further

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

What is the effect of side chain modification in the globular regions of histones

A

they can directly affect the chromatin structure

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

What does phosphorylation do to histones

A

(ser, thr, thy); addition of a negative charge; repulsion

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

What does acetylation do to histones

A

(to Lys) eliminates the positive charge; loss of association on DNA; DNA is more accessible

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

What does methylation do to histones

A

(to Lys, Arg) regulates interactions; methyl must be recognized by other proteins

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

What does ubiquination do to histones

A

(to Lys) regulates interactions, targets for degradation

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

Which proteins are considered writers

A

acetylases, methylases, kinases

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

Which proteins are considered erasers

A

deacetylases, demethylases, phosphatases

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

Which proteins are considered readers

A

bromodomain and chromodomain proteins, PHD finger, WD40 repeats

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

What do histone acetyltransferases do

A

add acetyl groups to lysine side chains using acetyl-coa; HDACs do the opposite

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

What do histone methyltransferases do

A

add methyl groups to lysine and arginine; demethylases do the opposite

17
Q

what chromatin is more heavily acetylated

A

euchromatin; it is associated with active transport

18
Q

what does acetylation do

A

removes the positive charge from lysine side chains, which affects interactions with negatively charged DNA

19
Q

Acetylation and bromodomians

A

histone acetylation generates binding sites for bromodomains. The bromodomains then recruit other proteins like nucleosome remodeling complexes

20
Q

What is methylation associated with

A

activation or repression (depends on residue); position and modification are important for regulation

21
Q

methylation of lysine 9 in H3

A

asso with silent chromatin

22
Q

methylation of H3 lysine 4

A

asso with active chromatin

23
Q

What are chromodomains associated with

A

bind specific methylated lysines; transcriptional silencing

24
Q

Describe the histone hypothesis

A

different modification patterns act like switches to regulate different processes; the combination of different mods can send different signals to the cell

25
Q

How do histones interact with one another

A

histone modifications can influence one another

26
Q

phosphorylation of serine 10

A

promotes acetylation of lysine 14

27
Q

acetylation of lysine 14

A

inhibits methylation of lysine 9

28
Q

How was/is histone localization to DNA determined experimentally

A

ChIP (basically); components were crosslinked, digested by micrococcal nuclease (only cuts linker), visualized by gel electrophoresis; resulted in the beads on a string model; modern sequencing is used to determine the specific sequence the histone is bound to

29
Q

What was observed after DNA was mapped onto chromosomes

A

nucleosomes are not evenly distributed and in some cases nucleosome locations are “fuzzy”

Molecular Biology (7 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions