Chapter 12 Flashcards
Base pairing
The nearly perfect fit between A-T and G-C nucleotides
Bacteriophage
A kind of virus that infects bacteria. Enters a bacterium, attaches to the surface of the cell and injects genetic information into it
Replication
When cells duplicate their DNA
DNA polymerase
An enzyme that joins individual nucleotides to produce a new strand of DNA
Telomeres
Tips of eukaryotic chromosomes
Griffith
Discovered transformation by infecting mice with virulent (S Strain) or avirulent (R String) pneumonia; heat-killed S strain + Living R strain= live S strain (from dead mice). <– thought a gene was responsible
Avery
Used enzymes to destroy macromolecules one by one; when DNA was destroyed no transformation (people still skeptical)
Hershey/Chase
Radioactive labels on either proteins(s) or DNA(p) of bacteriophages (viruses that infect bacteria) DNA in (DNA is it!)
Chargaff
Came up with the rule that A=T and C=G (true for all organisms)
Franklin
X-ray diffraction patterns depicted a double helix no Nobel Prize
Watson/Crick
Determine the model of DNA molecule by scooping everyone
Roles of DNA
- store info
- copy info
- transmit info
Components of DNA
- 5 Carbon sugar (ribose and dioxyribose)
- phosphate group
- nitrogenous base (4 for DNA, 4 for RNA)
- Monomer=nucleotide
- polymer=nucleic acid
DNA Structure
- antiparallel strands
- sugar-phosphate backbone (covalent)
- base pairs (nitrogenous bases make the rungs; H-Bonds)
Replication steps
- Starts at a fork where strands split
- DNA polymerase ads nucleotides and proofreads
- telomeres get shorter over time (except in cancer cells) immortal due to telomeres
