Brainscape's Knowledge GenomeTM

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


See full index

Molecular biology > Lecture 7 - Genomes > Flashcards

Lecture 7 - Genomes Flashcards

1
Q

What is the first level of packaging of DNA?

A

Beads on a string

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

What is Chromatin?

A

DNA extracted from the nucleus
DNA-protein complex
Proteins spaced at regular intervals

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

How was the composition of chromatin discovered?

A

Digestion with an endonuclease

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

What are histones?

A

The proteins in chromatins

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

What is Histone H1?

A

The linker histone
Attaches to the outside of the nucleosome

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

What is a chromatosome?

A

Made up of a nucleosome, DNA and a linker histone

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

What is a nucleosome?

A

DNA and histones together
Each one is made of 8 proteins

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

What is the second level of packaging of DNA?

A

The 30nm chromatin fibre

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

What is the 30nm chromatin fibre?

A

Decreases length of DNA to another 1/7th
Nucleosomes are stacked with non-neighbours and zig zag back and fourth
Nucleosomes connected by a straight DNA linekr

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

How is the 30nm chromatin stabilised?

A

The off axis asymmetric binding of histone H1 stabilises it

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

What is the importance of histones and nucleosomes?

A

Histones let DNA be packed into nucleosomes
The chemical modification of histones can change the structure of chromatin
Nucleosomes detach or shift to allow transcription of DNA
Nucleosomes detach for replication of DNA

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

What is euchromatin?

A

Contains active genes
DNA is in the form of the 30nm
Attached to the nuclear matrix and nuclear lamina so the DNA doesn’t get tangled up
Maintains shape of the nucleus

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

What is heterochromatin?

A

Contains inactive genes

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

What are the two types of heterochromatin?

A

Constitutive heterochromatin = tightly packed in all cells
Facultative heterochromatin = tightly packed in some cells

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

What is the highest level of DNA packaging?

A

The metaphase chromosome

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

What is the metaphase chromosome?

A

Centromeres hold the daughter chromosomes together
Has special histones, CENP-A not H3
Has attachment points for microtubules that pull chromosomes apart

17
Q

What are telomeres?

A

Protect the ends of chromosome from exonuclease attack and prevents them from being joined together by repair mechanisms

18
Q

What is a karyogram?

A

The complete set of metaphase chromosomes that are stained to give a banding pattern

Molecular biology (17 decks)

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