permiability and cell transport mechanisms

The experiment’s goal was to determine which substances require active transport and which travel passively through cell membranes, and how they do so. Diffusion and filtration are all methods for moving chemicals around cell membranes. The experiment’s goal was to learn how substances migrate through cell membranes, what forces drive this migration, and how diffusion and filtration play a role in the overall process.

Diffusion is a phenomenon that happens as particles of a matter diverge from a region with a large number of particles to an area with fewer particles until all regions have an equivalent number of particles. Diffusion is a gradual process that takes place over specific time periods depending on the concentration of substances in question as well as the intended area of coverage (Willis 125).

Osmosis is a type of diffusion involving the movement of water molecules across semi-permeable cell membranes. Osmosis is similar to diffusion in the sense that they are both passive and do not require any external force to facilitate the movement of particles from one point to another. Both diffusion and osmosis are essential for the normal functioning of in living organisms to help achieve a balanced number of molecules within their bodies. In animals, osmosis is the most important as it enhances the equal distribution of nutrients in the body’s cells across semipermeable membranes. However, diffusion takes place in the renal system where small and soluble molecules passively move into the Bowman’s capsules from the Glomerulus capsules. These molecules include urea, water glucose, and salts. In plants, for instance, osmosis ensures that cell membranes absorb water and other liquids, as diffusion enhances the flow of water, oxygen and carbon dioxide (Willis 125).

Filtration, on the other hand, is the process of separation of suspended particles in a solution from the fluid by a porous material. In this case, the particles are retained on the surface of the porous material while the fluid oases through. In animals, filtration occurs in the kidneys, specifically in the nephron. During the filtration process, blood passes under pressure via the walls of the Bowman’s capsule and glomerular capillaries. The filtrate or fluid contains water, sodium ions, potassium ions, chloride ions, small proteins and glucose.

Materials and Methods

PhysioEx 9.1

Cell Transport Mechanisms and Permeability-Exercise 1

Simulating Osmotic Pressure - Activity three

Simulating Filtration -Activity four

Results

Experiment data for Activity three- Simulating Osmotic Pressure

Run Number

Solute

MWCO

Start Conc. L

Press. L

1

Na+Cl-

20

5.00

170

1

Albumin

20

0.00

170

1

Glucose

20

0.00

170

2

Na+Cl-

20

10.00

340

2

Albumin

20

0.00

340

2

Glucose

20

0.00

340

3

Na+Cl-

50

10.00

0

3

Albumin

50

0.00

0

3

Glucose

50

0.00

0

4

Na+Cl-

100

0.00

136

4

Albumin

100

0.00

136

4

Glucose

100

8.00

136

5

Glucose

200

0.00

153

5

Albumin

200

9.00

153

5

Glucose

200

0.00

153

Experiment data for for Activity Four- Simulating Filtration

Run Number

Solute

MWCO

Pressure

Filter Rate

Start Conc.

Filter Conc.

1

Na+Cl-

20

50

1

5.0

0.00

1

Urea

20

50

1

5.0

0.00

1

Glucose

20

50

1

5.0

0.00

1

Powdered Charcoal

20

50

1

5.0

0.00

2

Na+Cl-

50

50

2.5

5.0

4.81

2

Urea

50

50

2.5

5.0

0.00

2

Glucose

50

50

2.5

5.0

0.00

2

Powdered Charcoal

50

50

2.5

5.0

0.00

3

Na+Cl-

200

50

10

5.0

4.81

3

Urea

200

50

10

5.0

4.74

3

Glucose

200

50

10

5.0

4.39

3

Powdered Charcoal

200

50

10

5.0

0.00

Discussion

From the experiment in Activity Three, we noted that an increase in the Sodium Chloride ions increases the osmotic pressure since the membrane was not permeable enough for was not permeable enough for Sodium Chloride ions to diffuse. It was also noted that the membrane 20 MWCO did not allow for ions to pass and that a solute was able to diffuse across a membrane only when at equilibrium phase. We further noted that if we doubled the concentration of a non-diffusible solute, the osmotic pressure also doubled.

Activity four experiments illustrated that enlarging the pore size of the membrane increased the filtration rate since bigger sized particles of solutes were able to pass making the filtration process faster. We also noted that Sodium Chloride ions maintained the highest concentration in the filtrate. Under all the filtration pressures, we noticed that powdered charcoal did not go into the filtrate as there were no traces of the same.

Works Cited

Willis, Scott A., et al. “Diffusion: definition, description, and measurement.” Modern NMR Techniques for Synthetic Chemistry (2014): 125-175.