11.2 Pentoses# of Nucleotides Know these structures too D- ribose核糖( in rna) 2-deoxy-D-ribose(in DNA) The difference-2 -oh vs 2-H This difference affects secondary structure and stability
11.2 Pentoses戊糖 of Nucleotides Know these structures too • D-ribose 核糖 (in RNA) • 2-deoxy-D-ribose (in DNA) • The difference - 2'-OH vs 2'-H • This difference affects secondary structure and stability
H H-C-OH HOCH OH H—C—OH AKH H I H→C-OH OH OH H.COH Furanose form of D-Ribose D-Ribose β D-Ribofuranose H H一C—H HOCHo O OH Hc—OH H I H H H—C—OH 3 OH H H.COH Furanose form of D-2-Deoxyribose D-2-Deoxyribose B-D-2-Deoxyribofuranose
ll.3 Nucleosides被 Linkage ofa base to a sugar Base is linked via a glycosidic bond(糖苷键) The carbon of the glycosidic bond is anomeric异头物 Named by adding -idine to the root name of a pyrimidine or-osine to the root name of a purine · Conformation can be syn(顺) or anti(反) Sugars make nucleosides more water-soluble than free bases
11.3 Nucleosides核苷 Linkage of a base to a sugar • Base is linked via a glycosidic bond （糖苷键） • The carbon of the glycosidic bond is anomeric 异头物 • Named by adding -idine to the root name of a pyrimidine or -osine to the root name of a purine • Conformation can be syn（顺） or anti （反） • Sugars make nucleosides more water-soluble than free bases
3 HOCH2 o NI2 O HH H OH OH 阝N1 I-glycosidic bond in pyrimidine ribonucleosides 6 HOCH2 O、N9= 4H H H H OHOH B-Ng-glycosidic bond in purine ribonucleosides
NH O NH HOCH N HOCH2 O HOCH H OH OH OHOH OH OH Cytidine Uridine Adenosine H Hypoxanthine HOCHe NH2 HOCHe o H OH OH OH OH Guanosine Inosine, an uncommon nucleoside