Principles and Processes of Biotechnology Flashcards
Biotechnology
Biotechnology is the technique of using live organisms or enzymes from organisms to produce products and processes useful to mankind
Principles of biotechnology
- Genetic Engineering (alter the chemistry of DNA/RNA and introduce into host organisms)
- Maintenance of sterile environment for all genetic engineering processes
Cell lysis
Isolation of genomic DNA from bacteria/plant/animal cell
Tools of recombinant DNA technology
- Restriction enzymes
- Palindrome sequence
- Ligase
What are restriction enzymes
- They are molecular scissors/chemical scalpels
- Cut the DNA at specific sites into fragments
- E.g. EcoR1 (Escherichia coli) and Bam HI (Bacillus amyloliquifaciens)
Palindrome sequence
It is a sequence of base pairs that reads same in both strands when orientation of reading is kept the same
Ligase
Group of enzymes that carry out sealing, annealing or joining of DNA fragments
Cloning vectors
Plasmids
Bacteriophages
Features of a cloning vector
- Ability to replicate within a bacterial cell independent of the control of the chromosomal DNA
- Plasmids are lesser in a bacterial cell
- Phages are very large in number in a bacterial cell
Features of plasmids
- Small circular DNA molecules
- Self-replicating and exists in single or multiple copies
- Confers antibiotic resistance to the host cell
- Smaller in size than host (bacterial) chromosome
Phages
Usually have linear DNA molecules into which foreign DNA can be inserted
Cloning of a DNA fragment in a plasmid vector
- On a foreign DNA, the gene of interest is identified and isolated
- The cloning vector (plasmid) is also identified from the bacterial cell.
- Using the same restriction enzyme, both are cut
- The gene of interest is then ligated using ligase enzyme into the plasmid vector
- now it is called a recombinant plasmid vector
- It is then incorporated into the bacterial cell
- The bacterial cell is introduced into a culture medium
- Multiple copies of the desired gene of interest can be produced
Dolly
- Dolly was a female domestic sheep and the first mammal cloned from an adult somatic cell, using the process of nuclear transfer
- Birth: 5th July 1996
- Death: 14th February 2003
Write briefly the steps taken in cloning Dolly
- Donor egg cell + Mammary cell from sheep udder
- Enucleation of egg cell- so that it will read and duplicate the DNA of the donor cell
- Combine cells using an electric shock; the combined cell now has a single nucleus from the nuclear donor
- Combined cells divide to form a blastocyst (8 blastomeres)
- It is placed in the uterus of a surrogate ewe
- Blastocyst develops into a fetus and in ~5 months a lamb is born
Gene cloning
Molecular biology technique that makes many identical copies of a piece of DNA, such as a gene.
In a typical cloning experiment, a target gene is inserted into a circular piece of DNA called a plasmid.