: RBCs has an enzyme called glucose 6- phosphatase dehydrogenase (G-6PD), which catalyse the initial step in oxidation of glucose via the hexose moriophosphate pathway. This pathway generate NADPH which is needed for maintenance of normal red cell fragility thereby maintaining the RBC size. Cytoskeleton of the RBC is made. up of protein called spectrin and is anchored to the transmembrane protein band by protein ankyrin which is also responsible for maintaining its shape and size.