Brainscape's Knowledge GenomeTM

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


See full index

Undeleted > Lecture 2 > Flashcards

Lecture 2 Flashcards

0
Q

No change in actual structure of the gene, no nucleotide change… change in chromatin structure which turns gene off or on… chromatin change acures in germ cells

A

epigenetics inheritence

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

a form of inheritance that is superimposed on the genetic inhertance based on DNA

A

epigenetics

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

DNA sequnce changes

A

genetic inheritence

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

high degree of conservation in a structure indicates

A

high degree of importance

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

one form of chromatin silences the genes it packages without regard to sequence and is directly inherited by daughter cells

A

heterochromatin

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

heterochromatin

A
  • heavily conserved
  • thought to be late replicating and genetically inactive
  • highly conserved at centromeres and telomeres
  • contains very few genes; resistant to gene expression
  • all the rest is less condensed and known as euchromatin
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

activity a gene depends on position on chromosome… will be silenced if relocated near heterochromatin

A

position effect.

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

breakage events that bring heterochromatin near active genes tends to silence them

A

position effect variegation…. zone of inactivation spreads a different distance in different cells

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

Histone modification

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

histone modification- loosens chromatin sturcutre

A

Acetylation of lysines… added by histone acetyl transferases (HATs); removed by histone deacetylase complexes (HDACs)

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

Histone modifications of serines

A

phosphorlation

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

What does recruitment of enzymes that cause histone modification depend on?

A

gene regulatory proteins

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

Are histone modifications reversible?

A

All are reversible, but can persist long after regulatory protieins have disappeared

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

What is important consequences for the types of proteins the modified DNA attract?

A

This determines the how when if gene expression takes place

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

What histone hast no variant histones?

A

H4

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

synthesized during S phase and assembled into nucleosomes on duaghter DNA helices just behind replication fork

A

major histones

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

synthesized during interphase and inserted into already formed chromatin. requires histone exchange process catalyzed by chromatin remodeling complex

A

variant histones

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

Histone code

A

thouseand of combinations of modifications (methylation, acetylation, etc)… ready by code reader complex

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

What binds and attracts other components??

A

code reader complex.. brings onther protein compexes

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

gene regulatory proteins has a histone modyfing enzyme “ writer”, the code-reader protein tells the other DNA about the change

A

code reader-writer

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

IS the chromatin remodeling comlex ATP dependent?

A

Yes,

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

How is remodeling contained to one area of the chromosome?

A

physical barriers… nuclear 4 complex, code reader complexes cannot go through
enzymatic barriers- HS4 region- protects the Beta globin locus from silencing, contains a cluster of histone actylase binding sites prevening writers from continuing

22
Q

centromeric heterochromatin

A

centromere specific H3 histon, CENP-A, pack the nucleosoomes into dense arrangements to for the kinetochore

23
Q

What does centromere sequences in humans consist of?

A

short repetitive DNA sequences called alpha satellite DNA

24
Q

What is centromerica heterochromatin defined by?

A

assembly of proteins, not DNA sequences

25
Q

alpha satellite DNA

A

at most centromeres, but not all. and at some areas that are not contromeres, the proteins that form to create the centromere is the MOST important aspect of centromere formation

26
Q

What are 2 altering types of chromatin

A

nucelosomes w CENP-A on the outside fold

Nucleosomes w normal H3 on the inside

27
Q

What does CENP-A do?

A

binds the kinetochore

28
Q

What does de novo centromere formation require?

A

a “seeding” event on alpha satellite DNA

29
Q

How are H3-H4 tetramers inherited?

A

Directly inherited by the daughter strands at the replication fork

30
Q

Centromeres are not randomly placed on

A

chromosomes

31
Q

structure of interphase chromosomes

A

extended loops to be more accesible

32
Q

What is assocated with nuclear lamina?

A

heterochromatin

33
Q

Each chromsomes occupies

A

its own areas of the nucleus, not each pair is next to one another

34
Q

Chromatin structure and location chagnes during

A

gene expression

35
Q

If a gene is being expressed it goes to?

A

a chromosomes loop

36
Q

decondensation of chromatin during gene transcription;

A

chromosomes puffs

37
Q

interior of nucleus very

A

hertogeneous

38
Q

mitotic chromosomes are

A

highly condensed, final levle in chromosome packaging

39
Q

two daughter DNA molecules replicated in interphase are speartely folded to produce

A

two sister chromatids

40
Q

What are chromatids held together at?

A

chromatids

41
Q

What is the purpose of consensation

A

protection of fragile DNA molecules

allow for separation for cell division

42
Q

Compaction aided by proteins called

A

condensisns

43
Q

genes that are similar in both sequence and fucntion due to common ancestry***

A

homologues… not the same as syntany

44
Q

What is a major clue to gene and prtein function?

A

recognition of sequnce similarity

45
Q

gene sequences are more tightly conserved than…

A

genome structure…. size of genome, number of genes, size of introns, abundance of repetitive sequences can be quite different

46
Q

How do genomic changes occur??

A

mistakes in DNA replication and repair… rare in genetic material

47
Q

types of genetic changes

A

base pair substitutions…
more lg scale=
duplications, deletions, inversinos, translocations

48
Q

elimination of mutations that interfere with improant genetic functions

A

purifying selection

49
Q

a duplicated gene that has become irreversibly inactivated by multiple mutations

A

pseudogenes

50
Q

globin genes… duplication and divergence

A

intially there was one hemoglobin genes and now it has four.

51
Q

SNPs. single-nucleotide

A

points in the gneome where one group has one nucleotide and another group as another
variation occurs at a high rate (1% or more)

52
Q

CNVs- copy number variants

A

presence of many duplications and deletions of lg blocks of DNA
some blocks are common and others rare

Undeleted (56 decks)

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