Nucleic Acids 1231 DNA Double Nanowire

The basic building block of DNA, which is a nucleotide with the chemical structure sketched in Fig. 12.8, is more complex than an amino acid. It contains a five-membered desoxyribose sugar ring in the center with a phosphate group (P04H2) attached at one end, and a nucleic acid base R attached at the other end. The figure also indicates by arrows on the left side the attachment points to other nucleotides to form the sugar-phosphate backbone of a DNA strand. Figure 12.9 presents the structures of the four nucleotide bases that can attach to the sugar on the upper right of Fig. 12.8. It is clear from a comparison of Figs. 12.5 and 12.9 that the nucleic acid base molecules are about the same sizes as the amino acid molecules. The

0 0

Post a comment