Glucose is a molecule that is able to diffuse across the plasmamembrane with a diffusion coefficient (D) of 3 x 10-8 cm/sec.
a) If the concentration of glucose in plasma is 5 mM, and theintracellular glucose concentration is negligible (i.e. 0 mM), whatis the rate of glucose diffusion (J) into the cell? Assume that thethickness of the plasma membrane is 10 nm.
Glucose transport can be enhanced (facilitated) by a transportersuch as GLUT3, which has a Km of 1.5mM and transports glucose at amaximum rate (Vmax) of 104 molecules/sec. Using the equation: rate= Vmax ([S]/[S] + Km), how many molecules per second is each GLUT3able to transport when [S] is 5 mM? How much faster is this ratethan simple diffusion?
Fresh water fish do not survive in water with a high concentration of bicarbonate(HCO3-). Briefly explainwhy this is so.