Unit C Topic 3 - The Central Dogma of Biology Flashcards
Erwin Chargaff
A+T and C+G are in equal amounts in DNA (Paired)
Alfred Hershey and Martha Chase
Used radioactive labling to discover that DNA is heritable molecule passed between bacteria
Rosalind Franklin
Used X-rays and discovered DNA is a helix
James Watson and Francis Crick
Porduced the first sturctural model of DNA
What does DNA stand for
Deoxyribonucleic acid
Nucleotides structure
5 - carbon sugar, a phosphate group and a ring shaped nitrogen base (A T G C)
PUR As Gold
Purine nucleotides
Adenine and Guanine (double ringed structure)
CuT the PY
Pyrimidine nucleotides
Thymine and Cytosine (single ringed)
Structure of DNA
shape, structure, bonds
- Double helix
- two antiparalel strands of nucleotides
- nucleotide strands linked together by a sugar-phosphate backbone
- Nucleotide pairs linked by hydorgen bonds
Endosymbiosis Theory
Mitochondira and chloroplasts were once self-sustaining organisms
Where do you inherit Mitochondiral DNA from?
From your Mother
H T R D3 D1 L
DNA Replication steps
- Helicase unzips double helix
- Topoismerase prevents supercoiling
- RNA Primase moves along (3’-5’) and adds RNA primer (5’-3’)
- DNA Polymerase III begins at primer moves along the DNA 3’-5’ adding new DNA and adding more DNA 5’-3’
- DNA Polymerase I Replaces RNA primer with DNA
- Ligase seals the backbones
Leading strand
3’-5’, enzymes move toward replication fork
Lagging strand
5’-3’, enzymes move away from replication fork (makes gaps or Okazaki Fragments)
Semi-conservative relication
Each double-stranded DNA consists of one old parent strand and one newly produced strand
How accurate is DNA replication?
And why
Very accurate because the enzymes proofread the new DNA to look for and correct errors