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.
What’s the problem with gel electrophoresis technique
Human (experimental) error plays a role when analysing the DNA
If a plasmid is cut one how many strands will it produce
If a plasmid is cut twice how many strands will it produce
If a plasmid is cut three how many strands will it produce
If a simple strand of DNA is cut twice how many strands will it produce
1
2
3
3
Why is a buffer needed in the gel electrophoresis experiment
To carry the electric current
To keep the pH stable
Keep the gel from heating and melting
Why does the DNA solution stay in the wells and not rise to the surface like the buffer solution for
Because the DNA is mixed with sugar glycerol solution hah makes it heavier
Gene cloning method steps
- The gene of intrest is cut and mixed with plasmids also cut by the same restriction enzyme
- Some plasmids take up the gene some do not
- Plasmids must be placed into bacteria cells. Plasmids and bacteria cells are placed into micro test tubes withs solution of calcium chloride. This makes the bacteria more competent
Types of agar plates
Plate 1-control
Bacteria is added to nutrient broth only, this produces bacteria lawn
Why- to rest the agar plate grows bacteria
Plate 2-ampicilian plate
Ampicilian antibiotic and bacter is added to plate, this prodces bacteria colonies displaying plasmids
Why- all these bacteria contain plasmid we don’t know if the plasmid has the gene of intrest
Plate 3- blotting procedure
Plate 2 is pressed with filter paper which picks up small amounts of bacteria in the exact places
Filter paper is pressed on agar plate with tetracycline
Plate 3 blotting procedure what does the colonies that grow or that do grow represent
Colonies that don’t grow demonstrate they have the plasmid with the gene
Colonies that grow show they don’t have the plasmid with the gene
Technique to prevent contamination
Work near a bunsenburner flame which forms a heat umbrella stops other bacteria coming in and the wanted bacteria stays in
Gloves
Goggles
Coat lab
Fill out table
Photos
What is DNA profiling
A technique for genetic analysis which identifies the variations found in the DNA of every individual
How is DNA profiling used in crime cases
Str analysis (short tandem repeats) found in non coding DNA, microscopic evidence can be used, pcr amplifies sample and Str and then match it to suspect
How is DNA profiling used in paternity cases
Gel electrophoresis the length of alleles, the ones that don’t match with the mother have to match the length of the father
What is genetic screening
Screening of embryos, babies and adults to see if they have a risk of a genetic disorder
Pros to genetic screening
Ability to obtain personal genetic info
Ability to make lifestyle changes
Ability to prepare yourself and get support/know what to expect
Cons for genetic testing
Will insurance companies still insure you
Changing the gene pool reduces genetic diversity (almost like selective breeding) preental screening
Incomplete information about severity (can range significantly between people)
Could create a psychological and emotional unhealthy status
What is genetic engineering
The technology entailing all processes of altering the genetic material of a cell to make it capable of preforming desired functions
What’s genetically modified organisms (GMO) vs transgenic organisms and examples
Altered at DNA of own organism to give it a desired trait eg console resistant to persitires therefore rounds weeds sourndinf will die when sprayed and canola won’t
Organism that have been modified by combining DNA of different species eg a glofish is glowing jelly fish and fish
Social issues of genetically altered organisms
Who owns the genes
Does the benifits of gmo benifit only rich farmers as the poorer ones are forced to buy due to keep up with competition
What’s biological issues with genetically modified organisms
Limits genetic diversity
Limits gene pool (selective breeding)
Affects bees
Ethical issues with genetically altered organisms
Are we playing god?
Is it wrong or right?
Do we have the right to control this?
Is genetic engineering a human process that affects evolution?
What’s an epidemic disease
Refers to a contagious, infectious or viral disease that spreads to many people in one specific geographical area. Also defined when the amount of cases of the disease is far greater than usually expected
What’s a pandemic disease
Like an epidemic involves contagious disease however it is not isolated to one specific geographical region and has the potentiometer to included millions of people in many countries
What’s rational drug design
Determining of the structure and function of a target molecule and using this information to develop drug treatments
How does a drug work on
Either stimulates the activity of its target (agonist) or by blocking or inhibitory the activity of ids target (antagonist)
Steps of drug design
1 research disease conditions- determine the structure of target molecule (usually protein)
2. Use specific methods to determine the 3D shape of the molecule
3. Determine molecules used to form target structure (3D computers program used to design drug structure)
4. Designed drug synthesised tested and refined on animals
Drug is made available for use
Driagrms of how drugs work
Photos
What are reversible inhibitors
Used to control the enzyme activity. There is often an interaction between substrate or end product and enzymes control the reaction
What’s types of reversible inhibitors
Competitive inhibitor- blocks active site so substrate cannot bind
Noncompetitive inhibitor- the substrate can still bind to the active site but the rate of reaction is lowered
Allosteric enzyme inhibitor- the substrate cannot bind to the active site because the active site is distorted
What’s irreversible enzyme inhibitors and an example
They bind strongly to the groups of proteins and destroy its catalytic activity.
Eg poisons such as arsenic act as irreversible enzyme inhibitors its binds the enzyme altering its shape so the substrate can not bind
What is relenza
A drug created to help with the flu
How does relenza work
Virus covered in Enzymes
They are need by virus to get out of the virus its infected and infect other cells
Relenza inhibits the active site of the enzyme not letting the virus spread to other cells and rapidly slow downs the rate of overal infection and the immune response will be able to do that quicker before the virus spreads.
