ABSTRACT

Carbohydrates are the most abundant compounds in living organisms. However, their importance doesnotpurelyrelyinabundance,astheyplaykeyrolesincellfunctionality.Inplants,carbohydratesareutilizedforthesynthesisofvariousstructuralcomponents,andtheyareusedtotransportcarbonandenergybetweentissues(IglesiasandPodestá2005,Smith1999).Thecentralrole ofcarbohydratesintheenergeticmetabolismishighlightedintheglycolyticandtheoxidative pentose-P pathways. However, these pathways have another important role, as they serve as source ofintermediatesforthesynthesisofalargenumberofcellularcomponents,suchaslipids,nucleic acids,organicacids,andproteins.Also,carbohydratesarefundamentalcomponentsofstructural moleculeslikecellulose,themostabundantbiomolecule.Inaddition,sugarscanbecombinedwith othercompounds,likelipidsorproteins,toproduceglycolipidsandglycoproteins,whichplaykey roles related with cell structure and function (Iglesias and Podestá 2005, Smith 1999). On the other hand,carbohydratesarethemajorreserveandmobilizationconstituentsinplants,wheretheycan befoundasstarch,sucrose,fructans,andpolyols(IglesiasandPodestá2005,LoescherandEverard 2004, Smith 1999).