Movement across membranes –List the types of membrane transport and their energy source. – Explain saturation, competition, and specificity for any transport mechanism and demonstrate these graphically. – Write Fick’s law of diffusion and predict how changes in concentration gradient, membrane surface area, resistance, thickness and temperature will change the rate of diffusion.

Class problem: Draw an epithelial cell with the properties below. Label the mechanism and direction of molecule movement across the membrane. The epithelial cell moves the following across its membrane: - O 2 in and CO 2 out basolateral side - Na + from the lumen to the ECF - K + from the ECF to the lumen - C 6 H 12 O 6 from the lumen to the ECF Hint 1: Consider concentration gradients. Hint 2: Use four or five membrane transport proteins. Hint 3: Mechanisms of movement include simple diffusion, facilitated diffusion,primary and secondary active transport, exocytosis.

–Explain saturation, competition, and specificity for any transport mechanism and demonstrate these graphically. Objective 2

–Write Fick’s law of diffusion and predict how changes in concentration gradient, membrane surface area, resistance, thickness and temperature will change the rate of diffusion. Objective 3

Fick’s law of diffusion *Note text error