Unit 1 Key Area 1-3 Flashcards
What is DNA is composed of
Two chain of nucleotide
Base pairing rule
Adenine pairs with thymine
Guanine pairs with cytosine
Definition of a nucleotides
They are comprised of deoxyribose sugar, phosphate and a base
What the name of the bond between the deoxyribose sugar and phosphate
Sugar- phosphate bond
What are the bonds between the bases called
Weak hydrogen bonds
Two classification of cells
Prokaryotes
Eukaryotes
Where are mitochondria and chloroplast DNA inherited from
From the mother
Are mitochondria dna circular or linear
Circular
DNA is inside of what
Chromosomes
Two types of strands
Lagging and leading
DNA replication is
Semi-conserivate
What does semi-conserivate mean
It has one old parental strand and one new one
Where do polymerase add nucleotides
At the 3’end
In the leading strand
Dna polymerase adds complementary DNA nucleotides to thr lead strand continuously
Stages of the leading strand
- The weak hydrogen bonds break and the DNA unzips
- A DNA primer binds to the end of the 3’ to allow polymerase to add the DNA nucleotide
- Individual nucleotides aline wirh there complementary base. They become joined 3’ end of the primer.
Polymerase brings about thr formation of the sugar-phosphate bind between the primer and nucleotide.
How does lagging strand work
DNA polymerase adds complementary nucleotides to lagging strand in fragments
What sort of process is lagging strand
Discontinuous
What does ligase do
Seals the fragments together in the lagging strand
Where do primers bind yo leading strand
At the bottom in one place
At the 3’ end
Where do primer add to at the lagging strand
They bind at many places
DNA replication requirement
DNA
primer
Nucleotides and bases
DNA polymerase and ligase enzymes
A supply of atp
What does PCR allow
A specific section of DNA to be amplified in vitro
Steps of PCR
Step one. DNA is heated to 95°c this causes DNA to denatured and the strands separate
- DNA is cooled to 55°c for a few seconds. This allows primers to to bond to the separated DNA strands
- DNA is heated up to 75°c this allows heat-tolerrant DNA polymerase to replicate the dna be adding nucleotides to the 3’ of thr original DNA
How many times is PRC repeated
20-30 cycles