1.5 CRISPR-Cas9

Question 1

what is the CRISPR-Cas9 system

Answer 1

a tool for cutting DNA at a specifically targeted location

Question 2

there are two components to the CRISPR-Cas9 system, what are they

Answer 2

1. a DNA cutting protein called Cas9
2. an RNA molecule known as guide RNA (gRNA)

Question 3

the two components of the CRISPR-Cas9 system bound together form a complex that can do what

Answer 3

that can identify and cut out specific sections of DNA

Question 4

Basic rundown of bacteria and virus CRISPR-Cas9

Answer 4

the system is used by bacteria to protect themselves from the virus. – when the bacterium detects the presence of virus DNA, it produces two types of short RNA (one which contained sequence that matches the invading virus)

• these two RNA form a complex with a protein called Cas9

– Cas9 is a nuclease (enzyme) that can cut DNA
– when the matching sequence, known as guide RNA, finds its target within the viral genome, the Cas9 cuts the target DNA, disabling the virus.

Question 5

CRISPR-Cas9 can be done in a test tube or nucleus of living cell. (describe process in nucleus)

Answer 5

• once the Cas9 is inside the nucleus, it will lock onto a short sequence known as the PAM.
• the Cas9 will unzip the DNA, and match it to its target RNA,
• if the match is complete, the Cas9 will use two tiny molecular scissors to cut the DNA.
• when this happens, the ce;; tries to repair the cut, but the repair process is error prone, leading to mutations that can disable the gene – allows researchers to determine its function.