Biotechnology Flashcards
What is biotechnology?
We can use our knowledge of heredity to genetically engineer organisms
What are the 2 ways of selective breeding?
- Wait a long time for gene to be mutated to desired form
- Be able to conduct a controlled cross of two species, combining the best traits of both yielding desired phenotype
Explain how glucose is regulated in the body
- B islet cells in the pancreas sense glucose levels in the bloodstream, signals to body/liver when to release to insulin or glucagon
- When low on glucose, body releases glucagon, which signals to liver to release glucose into blood
- When you have too much glucose, body release insulin to start absorbing glucose into liver
What is diabetes?
In diabetes, islet cells are destroyed.
This means the body is no longer able to regulate glucose
How is insulin made?
A human gene is put into a cell (plasmid) and then put this gene into a bacteria
What is the purpose of Reverse transcriptase.
- Reverse transcriptase is when making a DNA copy of mRNA
Prokaryotes cannot splice, so the genes put into the bacteria cannot have any introns. The solution to this is reverse Transcriptase from a retrovirus (making a DNA copy of mRNA, called cDNA)
How is insulin found in mRNA?
It isn’t, you have to make cDNA from all mRNAs and code them all into bacteria
How do you know which reproduced bacteria has the desired plasmid?
- transformation is inefficient only a small % of bacteria is transformed. Solution: add an antibiotic resistance gene (Ampr) , and only genes that have plasmid will grow
How do you get cDNA into bacteria?
Put them in a plasmid that will replicate itself in the bacteria
What is a vector?
It is a plasmid used to carry the gene that is being cloned.
It consists of a plasmid being cut to be carried, and then attaching cDNA to each end and recreating a circle
How do you cut DNA to attach cDNA?
You use “restriction endonucleases”- they are proteins that identify 6 base pair stretches and cut both strands of DNA at that point
What is the advantage of a sticky end? How is it created?
A sticky end is created when restriction endonuclease cuts the DNA
- It allows ligation to be very efficient because it will attach to a complementary sticky end very easily
How does bacteria take up vectors?
-Bacteria takes up vectors by transformation.
cDNA is attached to plasmid vector using DNA ligase
What is a “cDNA library”?
A cDNA library is created when bacteria is spread onto plate with ampicillin. This is where a DNA probe comes into play
How do you make bacteria express insulin?
You use a promoter and terminator sequence so that it will be recognized as a gene
