Biology Flashcards
PCR is short for
Polymerase chain reaction
PCR what does it actually mean?
itβs a chain reaction (exponential multiplication) only of a fragement
Where is a PCR performed?
in a tube in a thermal cylinder in the lab
what components are needed for a PCR ?
original DNA (we want to copy) free floating nucleotides primer DNA polymerase
anology of original paper
original DNA (we want to copy)
anology of new paper and ink
free floating nucleotides
anology of bookmark
primer
anology of copying machine
DNA polymerase
what are the steps of PCR ?
- Denaturation 2. Hybridisation (or annealing) 3. Synthesis (or extension)
What is a primer for?
- it helps the polymerase to attach to the DNA ( a polymerase can attach to dsDNA only) 2. It marks the starting point of replication
why do we need two different primers?
we need a bookmark for start and stop (if not we would read forever ;)
Why perform a PCR ?
Copying DNA millionfold, so it gets visible to the human eye
how many DNA strands in a cell?
46 chromosomes = 46 double DNA strands
what is the aim of DNA-replication?
to create ONE identical copy of DNA
Helicase
unwinding & seperating the DNA-strands
DNA-Polymerase III
adding & binding nucleotides (continuous replication) -> nucleotides must be complementary
Primase
creates primers (so polymerase III can attach)
DNA-Polymerase III (2)
adding & binding nucleotides (discontinuous replication) -> formation of socalled OKAZAKI-fragments
Ligase
linking the OKAZAKI-fragements
nucleotide
hydrogen bonds
nitrogenous base
DNA
Deoxyribo Nucleic Acid
what is the name of the sugar group?
(deoxy) ribose
Base A
and Nucleotide A
Adenine
Adenosine