核糖(ribose) 戊醛糖 CHO CHO H-℃-OH H-C-OH OH H OH H-C OH H-C-OH H OH 41 H-C-OH H-C-OH OH CH2OH CH2OPO3H2 HOH,C 核糖 5一磷酸核糖 核糖 H OH CHO C C C CH2OH H OH H OH 3 2 1 4 5 5-磷酸核糖 H OH CHO C C C CH2OPO3H2 H OH H OH