Enzymes that manipulate DNA

Question 1

What is an endonuclease?

Answer 1

enzymes that can bind to and cut sugar-phosphate bonds. Most are found naturally in bacteria cells

Question 2

What is a restriction endonuclease?

Answer 2

any enzyme that cuts sugar phosphate bonds at specific recognition sites
(have a specific recognition sequence, and a specific cut site within that sequence)

Question 3

What is the function of a restriction endonuclease?

Answer 3

cut both strands of DNA and leave fragments.

Question 4

How many fragments will an RE leave after cutting the DNA?

Answer 4

If DNA is linear and cut once it will leave 2 fragments, if it is linear and cut twice it will leave 3 fragments ect. f = c + 1
If DNA is circular and cut once leaves 1 fragment, if cut twice leaves 2 fragments ect. f = c

Question 5

What are sticky ends?

Answer 5

the result of a staggered cut through double- stranded DNA by an endonuclease resulting in overhanging nucleotides

Question 6

What are blunt ends?

Answer 6

the result of a straight cut across the double-stranded DNA by an endonuclease resulting in no overhanging nucleotides

Question 7

What is a ligase?

Answer 7

Creates phosphodiester bonds between any two nucleotides. Can be DNA or RNA
Not specific to base sequence (can bond individual nucleotides to a sequence)

Question 8

What is polymerase?

Answer 8

Form nucleic acid polymers from nucleotide monomers. DNA polymerase –> DNA polymers

Question 9

Where is DNA polymerase used?

Answer 9

replication in our cells
amplification in a lab