BIOL 222 Lecture Notes - Lecture 11: Okazaki Fragments, Transfer Rna, Exonuclease
Document Summary
Biol 222 lecture 11 dna replication. Centromeres site of spindle fiber attachment. Telomeres ends of chromosomes: stabilize chromosomes and provide means for replicating chromosome ends t-loop specialized region on the trna molecule which acts as a special recognition site for the ribosome. Semi-conservative - each daughter duplex contains one parent strand and one newly synthesized strand. Parental strands must be unwound: requires disruption of hydrogen bonds. Replication fork region of unwound dna where active replication is taking place. Complementary base pairing provides the basis for the fidelity of dna replication. Requires dna template, dntps, dna polymerase (dnap), and other enzymes and protein factors: parental strands serve as template, grows in 5" to 3" direction. 3" hydroxyl group reacts with 5" triphosphate group of the free nucleotide. Replication is bidirectional: prokaryotes - initiation occurs at a sinlge origin of replication, eukaryotes initiation occurs at multiple origins of replication. Replication origin a particular sequence in a genome at which replication is initiated.
