BIOC 302 Lecture 2: Nucleic Acids - Lecture 2
Document Summary
Nucleotides can exist in one of 4 main conformations, referred to as sugar pucker : endo = same direction as 5" or base (up, exo = on the plane, it is named based on which carbon is popping out . Dna exists as a c2" endo allows it to have a regular pattern 3" oh is facing down, 5" c is facing up allows for the double helix structure. Rna exists as a c3" endo can"t do a regular structure. How the 3" oh relates to the 5" c does not allow it to go to a regular structure. Purines: 6-membered ring (2 ns, thymine (uracil) & cytosine, 2-ring system (4 ns, adenine & guanine. Both of these structures have n"s which can accept hydrogen pka important: pka = the ph at which the conjugate acids and bases are equal. Aromatic structures: all sp2 hybridized atoms (6 p orbitals. N has lone pair in both pyridine and pyrrole.
