BIOL10005 Lecture Notes - Lecture 11: Dna Ligase, Dna Replication, Electrical Network
LECTURE 11 - Manipulation of the genetic material
PCR
1. DENATURATION: Heat DNA strands to approx 90-95° to break H-bonds and
separate the DNA strands
2. BIND PRIMERS: Cool to approx 50° to anneal/attach primers (single stranded
DNA) which pair with the “region of interest” (at the 3’ end of DNA strands) initiate
replication
oPrimers indicate the region to be copied
oLarge amounts of unbound of nucleotides are also added
oReduced the temperature to allow H-bonds to form
3. Raise temp to 72°: Taq/DNA polymerase copies strands (i.e. by adding
nucleotides onto the primer to form new complementary strands of DNA)
DNA grows in 5’à3’ direction: nucleotides are added to the 3’ end of each strand
1. Cycle is repeated until enough DNA is formed
GEL ELECTROPHORESIS
DNA standard of known size
Separation technique that separates DNA fragments according to their size/charge
using an electric circuit
CLONING AND MANIPULATION OF DNA
Why?
oLarge scale production of specific protein products
HOW?
oCloning into plasmid
oPlasmid: naturally occurring in bacteria, circle DNA, self-replicating
Enzymes used:
oRestriction enzyme: cut DNA molecules at specific sequence
Sticky ends
oDNA ligase: join DNA fragments together during DNA replication
Also join diff DNA fragments with complementary ends together
Transformation:
oBacteria w/ new DNA = transformed
oNot all will have taken up the plasmid
oChecking to see whether bacteria has transformed: blue-white screening or
gel electrophoresis
Cloning DNA:
Allows us to examine gene function as well
oDelete gene
find more resources at oneclass.com
find more resources at oneclass.com
Document Summary
Denaturation: heat dna strands to approx 90-95 to break h-bonds and separate the dna strands. Bind primers: cool to approx 50 to anneal/attach primers (single stranded. Dna) which pair with the region of interest (at the 3" end of dna strands) initiate replication: primers indicate the region to be copied o. Large amounts of unbound of nucleotides are also added: reduced the temperature to allow h-bonds to form. Raise temp to 72 : taq/dna polymerase copies strands (i. e. by adding nucleotides onto the primer to form new complementary strands of dna) Dna grows in 5" 3" direction: nucleotides are added to the 3" end of each strand. Cycle is repeated until enough dna is formed. Separation technique that separates dna fragments according to their size/charge using an electric circuit. How: cloning into plasmid, plasmid: naturally occurring in bacteria, circle dna, self-replicating. Enzymes used: restriction enzyme: cut dna molecules at specific sequence.