MCB 124 Lecture Notes - Lecture 2: Ribose, Polynucleotide, Deoxyribose

• School: UC-Davis
• Department: Molecular and Cellular Biology
• Course: MCB 124
• Professor: Baldwin Enoch

Document Summary

Lecture 2- nucleic acids structures: what are the differences between dna and rna, nucleosides and nucleotides, building blocks are made of base+ribose= nucleoside, base+ribose+phosphate=nucleotides, ri(cid:271)ose (cid:894)(cid:1006)"oh(cid:895) a(cid:374)d deo(cid:454)(cid:455)(cid:396)i(cid:271)ose, base- flat aromatic nitrogen-containing heterocycles. And syn- when base is towards the sugar overlapping it: sugar puckers- rings of sugars, one molecule is above or below the plane, endo- atom out of plane is upwards from the base(dominant form). Water comes in and sugar ring opens up- unhappy and breaks the chain. Basepairs with adenine (hoogsteine): watson-crick base-pairing, adenine-thymine (a-t) E(cid:454): cpa (cid:271)ase step (cid:894) sa(cid:373)e as tpg (cid:271)e(cid:272)ause it"s a (cid:272)o(cid:373)pli(cid:373)e(cid:374)t(cid:895: there are 6 different base steps, helical twist- how much do you rotate your monomer, not flat. Axial rotation/base (360/10. 5: 25a in diameter (7bp give you a square , base-planes are nearly perpendicular to helix axis (0 degree tilt, slightly negative roll, 18 deg. Wide,8-9 a deep, can fit an alpha helix, a-t bp can fit in this.