CHY 204 Chapter Notes - Chapter 8: Pyrimidine, Purine, Dna Replication
20 Feb 2014
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Document Summary
Nucleotides are constituents of nucleic acids: dna & rna. A segment of a dna molec that contains the info req for synthesis of a func biological product, whether pro/rna is a gene. The storage & transmission of bio info are the only known func of dna. Nucleotides & nucleic acids have characteristic bases & pentoses: nucleotides have 3 components: 1) nitrogenous base (a, c, t, g, u) 2) a pentose & 3) a phosphate. Nucleosides only have all except the phosphate group. The nitrogenous bases are either pyrimidines (1 ring; c,t (dna), u (rna)) & purines (2 rings; a,g). The base of a nucleotide is joined covalently at n-1 of pyrimidines & n-9 of purines. In soln, the straight chain (aldehyde) & ring (beta furanose) forms of free ribose are in equil; rna contains only the ring form, b-d-ribofuranose vs. deoxyribose undergoes similar intercoversion in soln but dna exists solely as b-2"-deoxy-d-ribofuranose.
