what is recombiant dna technology
the labratory manipulation of dna in which DNA fragments from various sources are served, combined, and reinserted into living organsisms.
what are restriction enzymes used for
-used to cut dna into fragments
-identify and cut specific sequences of base pairs on DNA molecules (recignition site)
what 2 cuts are restriction enzymes capable of making
1.blunt end cut- restriction enzymes make a clean cut, the fragments do not have an overhang
2.sticky end cut- restrcition enzymes make a staggered cut and the fragments have an overhang
what cut is more common in recombiant dna technology
sticky ends used more often in dna technology
what can the unpaired bases in a sticky end do
unpaired bases in a sticky end can join 2 fragments of DNA together
Joining the 2 fragments in a sticky end(3)
-2 DNA fragments can only be joined together if they have been produced using the same restriction enzyme
-when 2 fragments of dna initially combine, theyre held together by H-bonds
-DNA ligase is used to complete the fusion by forming phosphodiester bonds.
Plasmids
-small circular pieces of dna found in bacteria
-plasmid is cut with same restriction enzymes as the target gene segment and placed in solution
-matching sticky ends connect
-bacteria will now express inserted gene
What is Gel Electrophoresis
Process used to seperate DNA fragments based on their relative lengths.
Explain gel electrophoresis
-DNA is treated with restriction enzymes to cut into different sizes
- treated DNA is placed in the wells
-DNA has a negative charge bc of phosphate groups
-when current is on, DNA will move towards the positive electrode
- small fragments will be able to move through the gel faster than large fragments (difference in resistance)
- result, DNA fragments of different sizes will be separated
