Please enable JavaScript.
Coggle requires JavaScript to display documents.
Chapter 16 - Coggle Diagram
Chapter 16
DNA Proofreading, Repair & Telomeres
Proofreading
DNA Pol exonuclease 3′->5′
Mismatch Repair
MutS/MutL analogue
Nucleotide Excision Repair
Nuclease cut
DNA Pol fill
Ligase seal
Mutation & Evolution
Source of variation
Telomere Shortening
Repeated TTAGGG
Telomerase in germ cells
Reverse transcriptase
Cancer cell immortality link
DNA Replication
Semiconservative Mechanism
Meselson‑Stahl 15N/14N
Origins & Forks
Replication bubble
Helicase -> unwinding
SSB proteins stabilize
Leading vs Lagging
Primase RNA primer
DNA Pol III elongation
Continuous 5′->3′
leading
Okazaki fragments
lagging
DNA Pol I -> primer removal
Ligase seals nicks
Replication Machine
Sliding clamp
Trombone loop model
Topoisomerase relieves strain
Chromosome Organization
Prokaryotic DNA
Circular chromosome
Supercoiled nucleoid
Eukaryotic Chromatin
Histone octamer
Nucleosome “bead”
30‑nm fiber
Looped domains
Euchromatin vs Heterochromatin
Gene expression access
Epigenetic Modifications
Histone acetylation (up) transcription
DNA methylation (down) transcription
DNA as the Genetic Material
Historical Evidence
Griffith transformation
S vs R strains
Heat‑killed + live R -> pathogenic
Avery, McCarty, MacLeod
DNA = “transforming substance”
Hershey–Chase phage
32P DNA vs 35S protein
DNA enters E. coli
DNA Chemistry
Nucleotide structure
Deoxyribose
Phosphate
Nitrogen base
Chargaff’s rules
A = T
G = C
Double‑Helix Model
Franklin X‑ray photo 51
Watson‑Crick antiparallel strands
5′->3′ / 3′->5′
Complementary base‑pairing
Purine‑pyrimidine width
H‑bonds (A‑T 2, G‑C 3)