D and L Sugars D sugars can be degraded to the dextrorotatory(+)form of glyceraldehyde. L sugars can be degraded to the levorotatory(-)form of glyceraldehyde. CHO C02↑ H一C一OH CHO C02↑ HO-C-H degrade HO一C-H degrade CHO CO2 H-C-OH H-C-OH H一C-OH CHO H一C一OH H一C一OH H一C- OH degrade H一C一OH CH2OH CH2OH CH,OH CH2OH D-(+)-glucose D-(-)-arabinose D-(-)-erythrose D-(+)-glyceraldehyde Chapter 23 5 => Chapter 23 5 D and L Sugars • D sugars can be degraded to the dextrorotatory (+) form of glyceraldehyde. • L sugars can be degraded to the levorotatory (-) form of glyceraldehyde. =>