Part D: Lecture 31

Question 1

Function of restriction enzymes in nature

Answer 1

used by bacteria to cut virus DNA in vivo (prevention of infection by bacteriophage)

Question 2

bacteriophages (def.)

Answer 2

viruses that attack bacteria (inject DNA into cells, take over cell, killing it)

Question 3

Restriction enzymes (RE) are protein ___

Answer 3

homodimer

Question 4

RE targets ___bp sequences (ex.GAATTC)

Answer 4

4 to 8 bp

Question 5

RE targets cut sites in _____

Answer 5

foreign DNA

Question 6

enzyme type that prevents RE action on host DNA

Answer 6

methyltransferase

Question 7

methyltransferase action

Answer 7

find cut sites of RE on host DNA and adds methyl group (methylates) on both strands of DNA

Question 8

RE + methyltransferase example

Answer 8

-EcoRI
-M-EcoRI

Question 9

RE as a tool

Answer 9

used by scientists to cut DNA in vitro

Question 10

How RE is named?

Answer 10

-species, strain, and order of discovery
ex. EcoRI (E.coli RY13, 1st enzyme)

Question 11

2 differences between RE

Answer 11

-target site
-type of cut

Question 12

Most cut sites are ____

Answer 12

palindromes (same order 5′ to 3′ on both strands)

Question 13

cut sites found on google ___

Answer 13

“NEB”

Question 14

1 units of RE can digest _____

Answer 14

1 ug of DNA in 1 hour

Question 15

Tube of RE stored in ___ to _____

Answer 15

glycerol
stop protein for degrading during transport

Question 16

Tube of 10x buffer contains ___

Answer 16

optimal pH, Na+, Mg +

Question 17

RE digest reaction method contains

Answer 17

DNA
Water
2 ul of 10x buffer
1 ul of RE
@ 37 C (body temp)