CAS NE 102 Lecture Notes - Lecture 2: Histone H1, Spindle Apparatus, Mitosis
20 Jul 2016
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Document Summary
Pic of phosphodiester linkage: covalent bond between nucleotides in dna. 5" to 3" refers to what remains free at the 5" end or 3" end of the sugar of the first/last nucleotide added in the chain. Group 5 carbon: phosphate in position 5 unbound---start. Group 3 carbon: hydroxyl group in position 3 unbound----finish. Phosphate in position 5 of nucleotide binds to hydroxyl group in position 3 of preceding nucleotide. Proofreading: synthesis has to be in 5" to 3" direction for proofreading. Can add a 5" phosphate group of a nucleotide to the newly free 3" hydroxyl group at the end of the nucleotide chain. Cannot add a 3" to a 5" end in the other direction. Dna synthesis would stop if proofreading were in 3" to 5" direction. Base pairing: adenine-thymine (2 h-bonds) easier to break** 2 strands of dna bound by h-bonds because: latches 2 strands together only temporarily. Genes contain info to make proteins: gene expression.
