上游充通大学 1 A Nucleic Acid Consists of 4 Kinds of Bases SHANGHAI JIAO TONG UNIVERSITY Linked to a Sugar-Phosphate Backbone 核糖和脱氧核糖： >五元糖 >核糖-mRNA >脱氧核糖-DNA 5 HO OH HO OH H HO OH HO Ribose Deoxyribose Figure 4.2 Ribose and deoxyribose.Atoms in sugar units are numbered with primes to distinguish them from atoms in bases.1 A Nucleic Acid Consists of 4 Kinds of Bases Linked to a Sugar-Phosphate Backbone Figure 4.2 Ribose and deoxyribose. Atoms in sugar units are numbered with primes to distinguish them from atoms in bases. 核糖和脱氧核糖：  五元糖  核糖 --- mRNA  脱氧核糖 --- DNA