monovalents like Na+ and K+ _____________ the membrane permeability while divalents lije Ca+2 ______________ the same.
Please answer in terms of increase or decrease and explain the same....
Expert answers only please.
Dear student,blank 1 has increase and 2nd blank is decrease.As Monovalent cations such as Rb+, Cs+, K+, Tris+ and choline+ decreased Na+ permeability when present at the vesicle outside at a concentration range of 10 to 100mm. Increasing Na+ concentrations from 10 to 100mm at the vesicle inside increased Na+ permeability. The temperature dependence of Na+ efflux revealed that the activation energy increased in the lower temperature range (0 to 10°C) when Ca2+ was present at the outside or at both sides, but not when present at the vesicle inside only or in the absence of Ca2+. The results suggest that the Ca2+ outside effect is due to binding of calcium to negatively charged phospholipids with a consequent reduction of both fluidity and Na+ permeability of the membrane. The Ca2+-inside effect most likely involves interaction with proteins with consequent increase in Na+ permeability.Regards.