BMS1062 Lecture 3: Lecture 3 _ The Manipulation of DNA based on its Structural Properties
Document Summary
Lecture 3 : the manipulation of dna based on structural properties. Structural and physical properties of dna the physical properties of dna arise from its structure namely: double stranded helix ( stability) complementary base pairings between strands ( number of hydrogen bonds will influence melting point. ) Melting point refers to the denaturation of dsdna, dsdna -> ssdna) higher amount of hydrogen bonds ( g- C bonds, higher the melting point) hydrogen bonding between the 2 strands that maintain the shape ( accounts for viscosity ) length and diameter ( accouts for stability) acidity due to its negatively charged phosphate groups. Dna is polyionic due to its high phosphate group content polyionic = containing many different ions as a result it is : soluble in aqueous/low salt solution a salt of na2+/mg2+ etc at neutral ph insoluble in alcohol. Mechanical shearing will also decrease viscosity (anything that interferes with the structural. Uv absorption integrity of dna will decrease viscosity)