DNA Replication Flashcards
Part of nucleotide that’s hydrophobic
Nitrogenous bases
Purines
- Double ringed
- A & G
- PuGA-2
Pyrimidines
- Single ringed
- C, T, U
- PyCUT-1
of H Bonds A-T make
2
of H bonds G-C makes
3
Phosphate End Numbering
5’
Sugar End Numbering
3’
Gregor Mendel
Experimented on pea plants to discover genes
Friedrich Miescher
- Isolated nuclei of WBC
- Nuclein: proteins w/P inside nucleus
Pheobus Levene
- Insolated RNA, DNA to find bases, PO4, sugar
- Proposed chain of nucleotides
Joachim Hammerling
Used algae to show genetic info in nucleus
Fredrick Griffith
Discovered transformation, picking up DNA for its own
Avery, Macleod, McCarty
- Mixed bacteria w/diff enzymes to see which molecule needed for transformation
- Proved DNA is genetic material/transformation
Hershey, Chase
Used radioactive S & P to prove DNA is genetic material
Watson, Crick
Created DNA structure & model
Erwin Chargaff
Found complementary base pairs & 1:1 ratio
Franklin, Wilkins
- Used x ray to find helical structure
- 10 base pairs per turn
Semiconservative replication
New DNA = 1 old + 1 new strand
Initiation
- DNA helicase unzips at origin of replication
- Replication bubble & fork form
- SSBs stops them from rebinding
- Topoisomerase relieves tension
Replication Bubble
Forms unwound oval shape
Topoisomerase
Cuts DNA, uncoils it, reattaches them
Elongation
- RNA primers attach by primase to initiate base match up
- DNA polymerase 3 matches complementary bases w/nucleoside triphosphate
- DNA polymerase 1 removes primers, replaces them
- DNA ligase pieces okazaki fragments together
Leading strand
Towards replication fork
Lagging Strand
- Okazaki fragments
- Away from replication fork
DNA Polymerase 3 works in
5’-3’ (starts at 3’)
Termination
- Origin of replication joins together
- DNA separate from each other
- Double helix reforms
Nucleoid
Specific region where DNA is, but no membrane
Supercoiling is controlled by
Topoisomerase 1 & 2
Histones
Protein that gives structure for chromosomes
Nucleosomes
Grps of 8 histones w/double helix wrapped around it
Linker DNA
Connects nucleosomes
Similarities btwn Prokaryotes & Eukaryotes
- Has origin of replication
- Builds 5’-3’
- Leading & lagging strand
- Primers, polymerase
Differences btwn Prokaryotes & Eukaryotes
- Prokaryotes replicate faster
- Eukaryotes have more types of polymerase
- Eukaryotes have telomeres
DNA Polymerase 1 & 2
Proofreads
Telomeres
Repeating TTAGGG sequence to protect end of chromosomes
Telomerase
- Regenerates telomeres by adding more TTAGG using complementary bases
- Primers & polymerase adds on more bases
Genome
Complete set of DNA
Chromatin
Mixture of fibres (30 nm), protein that form chromosomes
Nucleoside Triphosphate
- Nitrogenous base + 3 PO4s
- 2 PO4s used for nrg for polymerase
- Base + PO4 created backbone
Meselson, Stahl
Showed DNA replication is semi conservative
