Brainscape's Knowledge GenomeTM

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


See full index

Control Of Gene Expression > Crispr Cas > Flashcards

Crispr Cas Flashcards

1
Q

Crispr cas in humans is used for genome editing what does this mean

A

Inserting deleting or altering genes using nucleases

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

What are cas

A

Crispr associated proteins

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

Why is crispr cas found in 40% of bacterial genomes

A

For adaptive immunity against viral infections

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

What 3 component complex makes the crispr cas bacteria system

A

Cas 9 protein nuclease
Cr rna (protospacers)
Tracr rna

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

What cleaves invading viral dna into protospacers (cr rna)

A

Cas 1 and 2

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

What happens once protospacers cr rna are made from cas 1 and 2 viral cleavage

A

Incorporated into the crispr locus

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

Why are protospacers incorporated to crispr locus in bacteria

A

If reinfection via that same virus occurs, protospacers can guide and bind to cas 9 to the viral dna complementary/ homologous to protospacers cr rna

Cas 9 then cleave phage dna

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

What makes up the crispr locus

A

Tracr rna

Cas operon (for diff types of cas proteins)

Protospacers cr rna

In between cr rna there are repeat arrays

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

What Hetero dimerises to form guide rna

A

Tracr rna and cr rna protospacers

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

What is the diff between type 1/ or 3 cas and type 2

A

1 and 3 types are multisubunit

Type 2 is multi domain

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

What type of cas is 2 and 3

A

A type 1 and 3 multisubunit cas

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

What type of cas is 9

A

Type 2 multi domain

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

Which domain of cas 9 binds g rna

A

Rec 1 and 2

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

Which lobe of cas 9 is responsible for cleaving comp dna, non comp dna , and Pam interaction

A

NUC lobe

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

What is Pam and why is it important

A

Sequence on invading dna upstream or down of the protospacer dna comp sequence which allows cas9 to detect self bacterial dna and non self dna

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

Does cas 9 cleave invading dna if they am site is not near to grna binding sequence

A

No. Cas 9 needs Pam to cleave

17
Q

Is pam found in crispr locus

A

No

18
Q

How have tracr rna and cr rna been simplified into 1 g rna for genome editing

A

Linkage through a linker loop

19
Q

What does deposition of a cas 9 g rna cause on a specific target site

A

Gene knock in or out because of the repair system

20
Q

How are cas 9 and g rna up regulated / expressed for genome eidditjng

A

in vitro plasmid with cas 9 and g rnawhich gets transacted into euk cell for expression

21
Q

How is grna/cas9 made specific for genome editing

A

G rna is comp to 1 of the dna strands in a specific target gene for example. The dna has a Pam sequence adjacent to the protospacer sequence target

22
Q

What causes repair system stimulation

A

Double strand break via nucleases in cas

23
Q

Which repair pathway causes a gene knockout due to it being error prone

A

Non homologous end joining NHEJ

24
Q

How does NHEJ cause gene knockouts by degrading mrna

A

Addition of nucleotides by terminal transferases on the dna breaks causes insertion or deletion. Insertion can cause PTCs

PTCs mean exon junction complexes EJCs won’t be knocked off by ribosomes

Recruit upf proteins for degradation of rna (NMD)

25
Q

Which type of repair system causes gene knock in

A

Homology directed repair

26
Q

How does homology directed repair work

A

The cut gene target by cas9 undergoes homologous recombination with a sister chromatid of desired target gene

Because the cut site on dna has homology arms to the sister chromatid which will exchange the gene of interest forming knock in

27
Q

What phase do chromatids need to be in for homology directed repair HDR

A

S phase

28
Q

How is crispr cas delivered ex vivo and in vivo

A

Ex vivo via removal of cells then put back in

In vivo putting cas crispr delivered into organ

29
Q

How can crispr be used to treat hiv

A

Cause gene knockout in ccr5 by inducing a mutation via nhej for example

Control Of Gene Expression (13 decks)

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