Chapter 6 - Biotechnology tools + techniques Flashcards
what are the four tools used in biotechnology
- Restriction enzymes
- DNA ligase
- DNA polymerase
- Primers
what are the 4 main techniques used in biotechnology
- DNA sequencing
- Polymerase Chain Reaction (PCR)
- Gel electrophoresis
- Recombinant DNA technology
what is traditional biotechnology
involves purposefully selecting organisms with desirable and useful traits for breeding and cultivation
what are restriction enzymes (restriction endonucleases)
Enzymes that cut DNA molecules at recognition sites. Two types of cuts: Sticky and blunt ends
what are sticky end cuts
One strand has overhanging complementary bases, is specific. Created when a restriction enzyme cuts DNA at different positions on each of the two strands
what are blunt end cuts
No overhang, not specific. Created when a restriction enzyme cuts DNA at the same position on both strands
what are recognition sites
A specific sequence of DNA at which a restriction enzyme will cut
what is DNA ligase
Enzyme used to catalyse the formation of a bond between two pieces of DNA
what is DNA polymerase
Enzyme that synthesises new strand of DNA based on a template strand and according to complementary base pair rules
What are primers
Short fragments of single stranded DNA or RNA. Assist in the synthesis of new strands of DNA by acting as a signal for the polymerase to begin synthesis
what is a restriction fragment
a short fragment of DNA generated when a restriction enzyme cuts a longer DNA sequence
what are the advantages of blunt end cuts
Fragments can join with any other blunt end fragment, non specific
what are the advantages of sticky end cuts
fragments can join efficiently with a desired fragment that is cut with the same restriction enzyme. Can produce specific products at faster rate, is specific,
how does DNA ligase work
by forming a phosphodiester bond between two fragments of DNA. Joins the 3’ hydroxyl end of one nucleotide to the 5’ phosphate end of another nucleotide
How is DNA ligase used on sticky end cuts
Two DNA fragments that have been cut with the same enzyme will have identical sticky ends, and thus complementary bases will be exposed. DNA ligase can then be used to recombine these two fragments even if they are from two unrelated organisms
How does DNA ligase work on blunt end cuts
Without the complimentary overhangs there is no formation of hydrogen bonds to stabilise the structure, process is less efficient
What biotechnological processes would the techniques of PCR and gel electrophoresis be used
DNA sequencing, mapping, profiling and recombinant DNA methods
Annealing
In PCR, The process of joining separate strands of DNA together, by joining sticky ends, as a result of hydrogen bond pairing, occurs when temperature is lowered
genome
All of the genetic material contained in an organism or cell, includes chromosomes in the nucleus and DNA in mitochondria and chloroplast