Monosaccharide Sugar - carbohydrate consisting of a single sugar unit

• Have an aldehyde or a ketone group and 2-5 alcohol groups depending of the # of carbons

             o    Glucose  aldose
             o    Fructose  ketose

• Common sugars

             o    5-carbon sugars  have 4 alcohols and one aldehyde/ketone group  pentose
             o    6-carbon sugars  have 6 functional groups  hexose
             o    3-carbon sugars  have 3 functional groups  triose

• In solution monosaccharides 5-6 carbons long  form more stable ring structures

            o    the C=O group reacts with the -OH group to form an O link
            o    6 carbon chains...
                  Aldose  form 6 member ring
                   Ketose  form 5 member ring
            o    Pentose sugars form 5 member rings

• Glucose

            o    Chain structure
                  C3 has the OH on the other side
            o    Alpha α-glucose
                 C1 has the H above the plane of the ring and the OH below the plane
                 Starch and glycogen
            o    Beta β-Glucose
                 C1 has the H below the plane of the ring and the OH above the plane
                  Cellulose and chitan

• Many hexose structures resemble glucose but have a different orientation of the alcohol group

           o    Mannose has the orientation on C2 switched

           o    Galactose has the orientation on C4 switched