central vacuole, a water-filled volume enclosed by a membrane known as the tonoplast[1][2] that maintains the cell's turgor, controls movement of molecules between thecytosol and sap, stores useful material and digests waste proteins andorganelles.A cell wall composed of celluloseand hemicellulose, pectin and in many cases lignin, is secreted by theprotoplast on the outside of the cell membrane. This contrasts with the cell walls of fungi (which are made ofchitin), and of bacteria, which are made of peptidoglycan.Specialized cell-to-cell communication pathways known asplasmodesmata,[3] pores in the