Physioex 9 exercise 1
PHYSIO EX 1
Simulating Dialysis (Simple Diffusion)
1. Describe two variables that affect the rate of diffusion.
The temperature of the solutions and the difference in concentration of the ion or molecule between the sides of 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?
Since the chemical formula for urea is (NH2)2CO and its molecular weight is about 60. It will not diffuse through the 20 MWCO membrane because it does not ionize.
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?
Glucose will diffuse through the 200 MWCO membrane because its MW is 180. The MW of the protein albumin is much greater than 200 so it will not diffuse through the 200 MWCO membrane.
4. Put the following in order from smallest to largest molecular weight: glucose, sodium chloride, albumin, and urea.
Sodium chloride, urea, glucose, and albumin
Simulated Facilitated Diffusion
1. Explain one way in which facilitated diffusion is the same as simple diffusion and one way in which it differs.
They are the same as they are both passive processes and the solute can only diffuse down its concentration gradient. It is different as facilitated diffusion requires the presence of a membrane-bound carrier protein in order to occur. Furthermore, simple diffusion does not.
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?
With fewer carriers present they can become saturated and this will slow or stop the transport of glucose.
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
Simulating Dialysis (Simple Diffusion)
1. Describe two variables that affect the rate of diffusion.
The temperature of the solutions and the difference in concentration of the ion or molecule between the sides of 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?
Since the chemical formula for urea is (NH2)2CO and its molecular weight is about 60. It will not diffuse through the 20 MWCO membrane because it does not ionize.
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?
Glucose will diffuse through the 200 MWCO membrane because its MW is 180. The MW of the protein albumin is much greater than 200 so it will not diffuse through the 200 MWCO membrane.
4. Put the following in order from smallest to largest molecular weight: glucose, sodium chloride, albumin, and urea.
Sodium chloride, urea, glucose, and albumin
Simulated Facilitated Diffusion
1. Explain one way in which facilitated diffusion is the same as simple diffusion and one way in which it differs.
They are the same as they are both passive processes and the solute can only diffuse down its concentration gradient. It is different as facilitated diffusion requires the presence of a membrane-bound carrier protein in order to occur. Furthermore, simple diffusion does not.
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?
With fewer carriers present they can become saturated and this will slow or stop the transport of glucose.
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