DNA Tools and Biotechnology Flashcards
what is a gene?
a discrete unit of heredity information, AKA a DNA sequence
what is genetic engineering?
directly introducing new genes into an organism
what is a transgenic organism?
an organism who has been genetically engineered
what is recombinant DNA?
DNA from two or more different sources
(ex - a bacteria having human genes inserted into it is now recombinant as it has 2 sources of genetic information, bacterial and human)
what is sanger sequencing / dideoxy chain termination and how does it work?
a method for determining the nucleotide sequence of a SECTION of DNA, basically tags dideoxy DNA nucleotides a certain colour and records them from longest to shortest (atcccgA -> atcccG -> atccC -> atcC -> atC -> aT)
-this long to short DNA sequence can then be read using gel electrophoresis
-DNA nucleotides are dideoxy as this means a new bond cannot be formed after it is added
what is next generation sequencing and how does it work?
a method for determining the nucleotide sequence of a WHOLE GENOME:
-single strand is immobilized and copied w PCR
what are the 2 methods for copying DNA sequences?
-dna cloning
-polymerase chain reactions
what is DNA cloning and how is it performed?
a method of producing copies of a DNA strand:
-a target gene sequence is cut out with restriction enzymes
-this target gene is inserted into a plasmid [circular bit of DNA separate from normal DNA] by matching base pairs & using dna ligase
-this plasmid is inserted into a bacteria using a “heat shock” so it can enter
-bacteria then grows & replicates the target DNA along with it
what is PCR / polymerase chain reaction?
a method for copying a DNA sequence:
-DNA is denatured
-primers are added
-DNA polymerase creates a new chain from the primer location
what is gel electrophoresis and how does it work?
gel electrophoresis is a method for visualizing DNA that has been copied:
-DNA is put into wells near a negative electrode
-DNA moves across the gel slab to the positive electrode
-similar sized molecules travel together, creating seeable DNA bands on the gel
what is the difference between sanger sequencing and next generation sequencing?
-sanger = slower, more expensive, but more precise
-NGS = cheaper, faster, but can be less accurate
how can restriction enzymes help with DNA cloning?
-restriction enzymes can cut up DNA into 2 sequences, both of which have open ends called “sticky ends”
-we can take a DNA sequence we want to clone, join it with the sticky ends, and have DNA ligase glue them back together
