| Popis: |
Publisher Summary The small intestine performs two vital functions: (1) digestive-transport and (2) barrier-defensive. This chapter discusses the three-compartmental enzyme system of the enterocyte relating to its digestive and barrier functions. The three-compartmental model represents a further development of the sequential model that takes into account possible modes of distribution of enzymes in the compartments. The model characterizes the behavior of the enterocyte and its properties, taking into account the three structurized barriers, water flows, and autonomous premembranes layer. The model makes possible the demonstration of homeostasis of the processes of membrane hydrolysis and absorption by regulating not only respective enzyme and transport activities but also the rates of inflow and outflow of water. If the rate of transfer of substance because of diffusion is counter-balanced by the rate of their reverse transfer due to outflow water, it means that a selective penetration of monomers retains and that of larger molecules is excluded. |
