Physioex 9.0 Cell Transport Mechanisms

Only available on StudyMode
  • Download(s) : 4661
  • Published : January 23, 2013
Open Document
Text Preview
For Learning Centre use only

Activity 1: Simulating Dialysis (Simple Diffusion) Lab Report

Review Sheet Results

1.
2. Describe two Variables that affect the rate of diffusion.

The two variables that affect the rate of diffusion are:

A. The size of the molecule. The larger molecule will diffuse more slowly than the smaller molecule. B. The nature of plasma membrane. If the membrane is composed of lipid portion., only lipid soluble molecules can pass through while water molecules cannot.

3. Why do you think the urea was not able to diffuse through 20 MWCO? How well did the results compare with your predictions?

The urea was not able to diffuse through 20 MWCO because the size of the pores of 20 MWCO was too small to allow the large size of molecules of urea to pass through. Since, the molecular weight of urea is 60.07, the molecules of urea were too large to enter the pores of the 20 MWCO.

4. Describe the result of the attempts to diffuse glucose glucose and albumin through the 200 MWCO membrane. How well did the results compared with your predictions?

Glucose could diffuse through the 200 MWCO while albumin could not diffuse through such membrane. It was because there was difference of molecule weight between them. Glucose (C6H12O6) has a molecular weight of 180 g/mol and albumin, which is protein with 607 amino acids, each single amino acid is 135 g/mole, has a molecular weight of(607 x 135) 81945 g/mole. Since the molecular of albumin is quite larger in molecular weight compared with glucose, it is absolutely believed that albumin was not able to diffuse the 200 MWCO.

I obtained the results from the experiment supported my predictions because only glucose could diffuse through the 200 MWCO while albumin could not.

5. 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 Lab Report

Review Sheet Results

1. Explain one way in which facilitated diffusion is the same as simple diffusion and one way in which it is different from simple diffusion.

One way in which facilitated diffusion is the same as simple diffusion is that they both transport solutes with(or along or down) their concentration gradient and they do not required the energy of ATP to support the transport.

One way in which facilitated diffusion is different from simple diffusion is that facilitated diffusion requires the help of carrier proteins bound in the membrane to transport molecules across the membrane. On the other hand, simple diffusion does not require the help of membrane proteins.

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 result compare with your predictions?

When more glucose carriers were present, the rate of glucose transport increased. It was because with the increase in glucose carriers, more glucose molecules could bind to the carriers and that would result in an increase number of glucose molecules get across the membrane.

I obtained the results from the experiment supported my predictions because when there was an increase in number of glucose carriers, the rate of glucose transport would also increase with the help of facilitated diffusion.

3. Explain your prediction of the effect of Na+ Cl- might have on glucose transport. In other words, explain why you picked the choice you did. How well did the results compare with your prediction?

Na+ Cl- will have no effect on the rate on glucose transport since Na+ Cl- is transported through a simple diffusion without the help of a carrier protein. Adding Na+ Cl- will not affect the rate of glucose transport because the Na+ Cl- transport is completely independent from the glucose transport.

I obtained the...
tracking img