Differences between xylem and phloem. Bulk flow functions in long-distance transport. Active Transport Definition Types Examples Basic Anatomy And Physiology Biology Notes Biology Textbook This flow of sap occurs in a specialised network of cells called the sieve elements. . Tracheids and vessel elements. However diffusion is much too slow for long-distance transport within a plant such as the movement of water and minerals from roots to leaves. Vitamin B 6 vitB 6 or pyridoxine is a very important compound for general cellular metabolism Since its discovery in 1934 by György and colleagues it has been implicated as a co-factor in more than 140 biochemical reactions in the cell Although most vitB 6 co-catalyzed reactions are related to amino acid biosynthesis and catabolism vitB 6 also. Water and minerals and food are generally moved by a mass or bulk flow system. At the short-distance level within organs sucrose migrates f...