Fruktany. Czesc I. Charakterystyka fruktanow, wystepowanie i znaczenie w roslinach wyzszych

The characterization of fructan structure, occurrence, pathways of synthesis and possible functions in the light of current views are presented. Fructans are polymers of fructose. They occur in numerous species of higher plants, i.e. in vegetative tissues of temperate grasses and cereals. Fructans play a role as reserve carbohydrates. The possible rotes of fructans in cryoprotection and in osmotic potential regulation are also discussed. Fructans are synthesized from sucrose. Two enzymes are involved in fructan biosynthesis: sucrose fructosyl transferase (SST) and fructan fructosyl transferase (FFT). A fructan exohydrolase (FEH) catalyzes the depolymerization and remobilization of stored fructans.