BIOC 2580 Lecture Notes - Lecture 3: X-Ray Crystallography, Oswald Avery, Erwin Chargaff
1 Dec 2016
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Document Summary
Known as chemicals since 19th century = friedrich miescher first isolated them from nuclei of white blood cells in 1869: called it nuclein. Their vast biological significance was not appreciated until 1940s. Nucleic acids are made by connecting nucleotides via phosphodiester bonds. Therefore the repeating unit is the nucleotide. Nucleotide is built from three components: a sugar, a base, and a phosphate group. Two types of the nucleic acid sugars. The backbone of a nucleic acid is made from the sugars, linked together by the phosphates = sugar-phosphate backbone. The bases carry the genetic sequence information. Analogous to the peptide backbone of a protein. Nitrogenous bases in nucleic acids are derivatives of pyrimidines and purines. Pyrimidines and purines are heterocycles: heterocyles: an aromatic ring like benzene, except there are heteroatoms in the ring, heteroatoms: non-carbon atoms like n, o, s, in nucleic acid bases we will only see n. Both dna and rna contain 2 major pyrimidine bases.
