Last Sac Flashcards
What does polymerase do
Join base pairs
What does helicase do
Split
What does ligase do
Jo na sugar and phosphate strands
What is genetic engineering
Manipulation of an organisms genes
What’s a restriction enzyme (endonuclease)
Naturally occur in bacteria enzymes that allow genetic engineers to cut DNA in precise sequences called recognition sites
What’s a recognition sites
A precise sequence of 4 to 8 base pairs that restriction enzymes cut
What’s a sticky end
When a restriction enzyme cuts DNA it leave sticky ends that are exposed nucleotides that match other specific sticky ends and can join
What’s some examples of restriction enzymes
EcoR1
Hae 11
What is recombinant DNA
When DNA is cut form in organism by a restiriction enzyme and is placed into another piece of DNA in another organism, the new DNA is recombinant DNA
What’s very good to make recombinant DNA
Plasmids from bacteria
Steps of creating recombinant DNA
- Two pieces of DNA are cut by restriction enzymes producing sticky ends
- Ligation
-Fragments of DNA join by base pairing by the enzyme DNA ligament
- this produces recombinant DNA if the DNA joins from different sources
Annealing
When two matching sticky ends come together
These form either linear or circular molecule.
What are plasmids
Plasmids are vectors of DNA, can carry foregin DNA from any source
What’s the process of gene cloning
Once the plasmid has been removed from bacteria, cut the plasmid, inserted the required DNA and annealed plasmid to from recombinant DNA the plasmid must then return to the bacteria
Biologists use shock treatment to get bacteria to take up recombinant plasmids.
Once plasmid in the bacteria the bacteria will naturally use its ribosomes to produce proteins of the inserted gene
The plasmids will produce asexually, this means that the inserted gene will be replicated
What’s the polymerase chain reaction
A methods to create vast quantities of DNA identical to trace samples.
This is known as DNA AMPLIFICATION
Steps in the polymerase chain reaction (PCR)
- Seperate the target DNA strangers by heating the DNA.
- Add primers (short rna strands that provide starting sequence for DNA replication) nucleotides and DNA polymerase enzyme
- Incubate and cool. This allows primers to attach to single stranger DNA. DNA polymerase synthesises complementary strands
Repeat cycle and after a few ther eiwll be heaps more
What’s the pattern for numbers of target DNA produced in pcr
Rounds. DNA Start 1 1. 2 2. 4 3. 8 4. 16 5. 32 6. 64
Doubles every time
What is gel electrophoresis
Used to seperate DNA strange in the basis of their size
How to prepare DNA for electrophoresis
The DNA is cut into small pieces using restriction enzymes
Whic direction does DNA travel on gel electrophoresis and why
Moves towards the positive charge as it has a negative charge from the phosphate backbone
What’s the steps of gel electrophoresis
- DNA samples mixed with a dye are placed into wells and covered with buffer solution
- By applying the electric field to the solution the DNA moves toward the positive sections
- Molecules of different sizes will spread out with the ones moved furthest being the shortest.
- DNA markers are known lengths of DNA used to compare the unknown.