2: Micobiology: Biotechnology and Recombinant DNA Technology Flashcards
Over the years microbes have been used in the chemical production of what?
vaccines industrial enzymes foods vitamins antibiotics hormones etc.
What is biotechnology?
is the use of microorganisms or mammalian cells to carry out defined chemical processes fir industrial purposes.
What does Genetic Engineering encompasses what?
the many procedures used to join together DNA fragments to produce genes of interest and the procedures to introduce such recombinant DNA molecules into expression systems for large-scale production of proteins (or DNA) of interest.
What are the steps in Gene cloning?
the gene of interest (eg, insulin gene) is inserted into the vector DNA (eg, plasmid) in vitro.
the recombinant vector DNA is introduced into a host organism (eg, E. coli) where it can multiply.
Detection and purification of the desired clone.
the cell containing the recombinant vector is the grown in culture to form a clone of several genetically identical cells, each of which carries a coy of the vector.
the final step depends on whether the gene itself or the product of the gene is of interest.
What can the gene of interest be from?
- gene libraries containing either natural copies of genes or cDNA synthesized from the mRNA template reverse transcriptase.
- synthetic DNA
What happens to E. coli if it is treated with high concentrations of calcium ions and then stored in the cold?
becomes transformable at low efficiency.
What are Electroporation?
small pores are produced in the membranes of cells that are exposed to pulsed electrical fields. DNA molecules present outside the cells during the electrical pulse can then enter the cells through these pores.
What can large quantities of the gene of interest be harvested and used for?
a variety of purposes
eg, diagnostic DNA probes
What can be done if the gene of interest is expressed (ie, transcribed and translated) on the cell clone?
its protein product can be harvested
What are restrictions endonucleases?
certain bacteriophages failed to replicate in particular species of bacteria due to the rapid hydrolysis of the bacteriophage DNA by speific bacterial endonucleases = restriction endonucleases.
the first restriction enzymes were purified in 1970.
What is restriction endonuclease?
an enzyme that recognizes short specific palindromic sequences in double-stranded DNA and cleave the duplex.
What is a cloning vector?
is a plasmid or viral DNA into which foreign DNA may be inserted to be propagated in a host cell.
Cloning vectors are designed to allow what?
integration of foreign DNA at a restriction site that cuts the vector in a way that does not affect its replication.
What i the most important property of a vector?
self-replication.
once in a cell, a vector must be capable or replicating.
What is important about small size vectors?
small vectors are more easily manipulated than larger DNA molecules, which tend to be more fragile.