MBB 222 Lecture Notes - Lecture 16: Atp Hydrolysis, Inverted Repeat, Absorbance

• School: Simon Fraser University
• Department: Molec Biol & Biochem
• Course: MBB 222
• Professor: dr.chu

Document Summary

Word, phrase, or sequence that is spelled identically either forwards or backwards not the same as nucleic acid sequence that is the same written 5" to 3" on one strand or 5" to 3" on the complementary strand. An inverted repeat is a sequence of nucleotides followed downstream by its reverse complement which may contain intervening nucleotides: palindromes and inverted repeats can form unique structures: ** a260 changes depending on the structure of the dna - single- stranded or double-stranded. Hypochromic effect: decrease in absorption of uv light when bases are stacked: absorbance is quenched when strands come together. Hyperchromic effect: denaturation of dsdna results in an increase in absorption. Dna melting (denaturation) and re-annealing (re-naturation) can be followed by the change in absorbance at 260nm. Both the formation and the disruption of the dna double helix are highly cooperative - the strands hold tight until the melting point, tm, and then rapidly let go.