Cell Transport Mechanisms and Permeability
Lab Time/Date ___
Activity 1 Simulating Dialysis (Simple Diffusion)
1. Describe two variables that affect the rate of diffusion. Size of material and concentration
2. Why do you think the urea was not able to diffuse through the 20 MWCO membrane? How well did the results compare with your prediction? The molecules were too large to pass through. This is what I predicted on my Hypothesis.
3. Describe the results of the attempts to diffuse glucose and albumin through the 200 MWCO membrane. How well did the results compare with your prediction? The glucose diffused through the 200 MCWO membrane while the albumin didnt.
4. Put the following in order from smallest to largest molecular weight: glucose, sodium chloride, albumin, and urea. Sodium chloride urea glucose albumin
Activity 2 Simulated Facilitated Diffusion
1. Explain one way in which facilitated diffusion is the same as simple diffusion and one way in which it differs. One way that facilitated diffusion and simple diffusion are similar is the way they transport along or down the concentration gradient. One way these two differ is that simple diffusion occurs without the assistance of membrane proteins and facilitated diffusion requires a membrane bound carrier protein to assist in transport.
2. The larger value obtained when more glucose carriers were present corresponds to an increase in the rate of glucose transport. Explain why the rate increased. How well did the results compare with your prediction? The greater the concentration difference between one side of the membrane and the other, the greater the rate of facilitated diffusion.
3. Explain your prediction for the effect Na+Cl− might have on glucose transport. In other words, explain why you picked the choice that you did. How well did the results compare with your prediction?