BIOLOGY – CELL DIVISION

BIOLOGY – CELL DIVISION - -Replisome 1...

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BIOLOGY – CELL DIVISION S-PHASE - DNA – right turned double helix of two antiparallel covalently bonded glucose/phosphate backbones (held together by Hydrogen bonding AT/GC) - 5’ carbon has a phosphate group - 3’ carbon has a hydroxyl group - Strands are antiparallel - DNA polymerases can add bases to 3’ hydroxyl groups with properly paired bases. - Unwound 3’ end is leading/continuous side - Unwound 5’ end is the lagging/discontinuous strand (okazaki fragments) - Semiconservative – half of the new strand is new, half old. - Helicase unwinds helix (breaking Hydrogen bonds) - Primase adds RNA primers, which act as starting points for DNA polymerase. - DNA polymerase 3 is responsible for adding new base pairs - DNA polymerase 1 is responsible for removing RNA primers
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Unformatted text preview: -Replisome 1 organelle that holds all DNA replication materials (proteins, enzymes etc.)-Bidirectional replication forks allow for faster replication.-Most prokaryotes have a single bidirectional replication fork (circular chromosome). Their origin does not have to wait until replication is complete before they begin to replicate again-At the end of the 3 strand there is a gap left where RNA primer has been removed but there is nothing for the polymerase to connect to.-Telomerase (enzyme) adds DNA onto the 3 end from its own RNA template. Telomeres are repeated over and over again and primer is added to the new end, preventing the loss of DNA-Telomerase is active in germ cells and rapidly cycling cells (cancer cells)...
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This note was uploaded on 10/23/2008 for the course BIO 1222 taught by Professor Maxwell during the Spring '08 term at UWO.

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