Exercise 1
Exercise 1
Cell Transport Mechanisms and Permeability
Name ____________________________________________________________
Lab Time/Date ______________________________
Activity 1 Simulating Dialysis (Simple Diffusion) 1. Describe two variables that affect the rate of diffusion. * The size of the pores of the membrane * The size of the molecule diffusing through the membrane
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? * Because the pores of the membrane were not large enough * I predicted this correctly.
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?
I predicted that only glucose would diffuse through it and was right. Albumin is too heavy to diffuse through that membrane. 4. Put the following in order from smallest to largest molecular weight: glucose, sodium chloride, albumin, and urea.
NaCl, 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.
-Similar – They pass through the membrane without the use of ATP, they’re both forms of passive transport.
-Different - The solutes in facilitated diffusion pass through a carrier protein while the solutes pass through the membrane in simple diffusion.
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?
Since there were more carrier proteins, more glucose could diffuse into the cell at one time which made the process go along much quicker. I predicted this correctly.
3. Explain your prediction for the effect Na+Cl− might have on glucose transport. In other words, explain why you
Cell Transport Mechanisms and Permeability
Name ____________________________________________________________
Lab Time/Date ______________________________
Activity 1 Simulating Dialysis (Simple Diffusion) 1. Describe two variables that affect the rate of diffusion. * The size of the pores of the membrane * The size of the molecule diffusing through the membrane
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? * Because the pores of the membrane were not large enough * I predicted this correctly.
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?
I predicted that only glucose would diffuse through it and was right. Albumin is too heavy to diffuse through that membrane. 4. Put the following in order from smallest to largest molecular weight: glucose, sodium chloride, albumin, and urea.
NaCl, 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.
-Similar – They pass through the membrane without the use of ATP, they’re both forms of passive transport.
-Different - The solutes in facilitated diffusion pass through a carrier protein while the solutes pass through the membrane in simple diffusion.
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?
Since there were more carrier proteins, more glucose could diffuse into the cell at one time which made the process go along much quicker. I predicted this correctly.
3. Explain your prediction for the effect Na+Cl− might have on glucose transport. In other words, explain why you