DNA
A complex molecule containing the genetic information that makes up the chromosomes.
Purine bases
double ring, adenine and
... [Show More] guanine
Pyrimidine bases
single ring, cytosine, thymine, uracil
Bonding in DNA
Covalent bonds between C5 and PO and C3
Hydrogen bonds between bases
Components of DNA
Sugar, nitrogen-containing base, phosphate
Chargoff's Ratio
there is a 1:1 ration between A and T, as well as G and C
Rosalind Franklin
Woman who generated x-ray images of DNA, she provided Watson and Crick with key data about DNA
Pauling
thought DNA was a triple helix
Watson and Crick
Developed the double helix model of DNA.
H bonding and evolution
the closer a species is related to one another, the less missing hydrogen bonds there are between the base pairs, increasing the melting point
- more recent= higher melting point
semiconservative model
Type of DNA replication in which the replicated double helix consists of one old strand, derived from the old molecule, and one newly made strand.
Meselson-Stahl Experiment
Used isotope of nitrogen to change the weight of DNA N15 & N14, demonstrated that the semi-conservative model is the best description of replication. F1 showed one band, F2 showed two strands (conserved DNA and new strands)
Prokaryote DNA replication
DNA replication starts in 1 place continues in 2 different directions until the chromosome is copied. Goes around the ring of plasmid DNA
orgin of replication
Site where the replication of a DNA molecule begins, consisting of a specific sequence of nucleotides.
Topolisomerase
Protein that relieves strain on the helix of DNA during DNA replication
Helicase
An enzyme that untwists the double helix of DNA at the replication forks.
DNA polymerase
Enzyme involved in DNA replication that joins individual nucleotides to produce a DNA molecule. The enzyme has editing ability (RNA to DNA) and can also backtrack to fix mistake.
DNA replication
The process in which DNA makes a duplicate copy of itself.
leading strand
the new complementary DNA strand synthesized continuously along the template strand toward the replication fork in the mandatory 5' to 3' direction(of new DNA)
lagging strand
A discontinuously synthesized DNA strand that elongates by means of Okazaki fragments, each synthesized in a 5' to 3' direction away from the replication fork. Ligase enzyme then attaches Okazaki fragments and DNA polymerase changes RNA primers to DNA nucleotides [Show Less]