BIOL 117 Lecture Notes - Lecture 6: X-Ray Crystallography, Endergonic Reaction, Nitrogenous Base
Document Summary
Nucleic acid: a polymer of nucleotides: nucleotides have 1. a ve-carbon sugar 2. a phosphate 3. a nitrogenous base. Sugar phosphate backbone is joined through phosphodiester bonds: there is directionality to the sugar phosphate backbone. The phosphate end is the 5" end (phosphate ve ~: primary structure in nucleic acids is their nucleotide sequence, phosphorylation requires energy (endergonic) Dna"s secondary structure: watson and crick, dna is anti parallel, dna is a double helix, bases are on inside and backbone is outside, dna has two different sized grooves. Chargaff"s two rules: purine quantity always equals pyrimidine"s quanity, a=t c=g. Rosalind and wilkins calculated distances btwn groups of atoms in the dna molecule using x-ray crystallography. Dna polymerases: uni-directional (5"->3", dntd"s = dioxyriboneucleases triphosphates things. Replication bubbles = dna replication occurs in different directions at the same time: the ends of these bubbles are called replication bubbles. They bind to the separated strands of dna and prevents them from closing back up.
