Proving that Osmosis and Diffusion Occur in Artificial Membranes by Using a Dialysis Tubing
Hypothesis- Osmosis and diffusion will continue until equilibrium is
reached and net movement will no longer occur. Solute size and
concentration gradient across the selectively permeable membrane will
effect diffusion.
Materials- please refer to transport across semi-permeable membranes:
diffusion and osmosis laboratory exercise hand out.
Procedure: please refer to transport across semi-permeable membranes:
diffusion and osmosis laboratory exercise hand out.
Observations:
Table A:
Time
Dilute Lugol’s solution in beaker
Glucose and Starch solution in dialysis tube
Initial Observations
Clear yellow solution/ color changed into blue
Clear
After 10 minutes
More yellow than before/ reacted with benedict to form orange
Tubing became cloudy with movement and a little suspension
After 20 minutes
Dark yellow/ reacted with benedict to form a dark orange
Tube became a blue and purple solution with movement
Table B:
Solution inside dialysis tubing
Initial Mass (g)
14.66 g
Change in Mass (g)
15.74 g
Change in Mass (g)
1.08 g
Discussion/Analysis:
Based on the data collected and the results of the experiment, the
hypothesis was correct. The iodine diffused through the tubing, but
the molecules of starch/glucose solution were too large to diffuse
through the tubing. Iodine, which is a fluid and has very small
molecules, was able to diffuse through the dialysis tubing and reach
an equilibrium on the inside and outside of the tubing. This is proven
by the increase in the size of the tubing from the initial mass of
14.66 g to a final mass of 15.74 g. However, sucrose and starch are
macromolecules, so they were too large to diffuse through the tubing.
This was proven by the benedicts test of the outside area, it came up
negative, while the test of the tubing fluid came up slightly
positive. The dialysis tubing was found not to be a good model for a
We then took 1ml of the 10% glucose solution again using the glucose rinsed pipette and added it to test tube 1, we then filled the H2O rinsed pipette with 9ml of H2O and added it to test tube one; making 10ml of 1% solution.
However not in sucrose, the RBCs were semi-permeable. RBCs diffuse in the water around five minutes, but in glycerol RBCs diffuse in fifteen minutes. Several factors are involved that affect the rate at which the RBCs diffuse, could have been because of the size, polarity, or the charge of the molecule. Urea is the carbonic acid found in urine, blood, and lymph; it is formed in the liver from amino acids and ammonia. It is important that urea is permeable because the amount of urea in the body is essential because it helps undergo waste product. Glycerol is combination of sugar and alcohol. This solution is an important component for storage of fats that are ingested into the body as food, this one good reason why glycerol is permeable. Sucrose however has low permeability which is why sucrose has a slow rate of diffusion and glycerol and urea on the other hand has fast rates of
These labels indicated the lactose solution that was be placed into the mini-microfuge tubes. The varying lactose ph solutions were obtained. The four miniature pipets were then used, (one per solution,) to add 1mL of the solution to the corresponding mini-microfuge tubes. When this step is completed there were two mini-microfuge tubes that matched the paper towel. Then, once all of the solutions contained their respective lactose solutions, 0.5mL of the lactase enzyme suspension was added to the first mini-microfuge tube labeled LPH4 on the paper towel, and 4 on the microfuge tube. As soon as the lactase enzyme suspension was added to the mini-microfuge tube, the timer was started in stopwatch mode (increasing.) When the timer reached 7 minutes and 30 seconds, the glucose test strip was dipped into the created solution in the mini-microfuge tube for 2 seconds (keep timer going, as the timer is also needed for the glucose strip. Once the two seconds had elapsed, the test strip was immediately removed, and the excess solution was wiped gently on the side of the mini-microfuge tube. The timer was continued for 30 addition seconds. Once the timer reached 7:32 (the extra two seconds accounting for the glucose dip), the test strip was then compared the glucose test strip color chart that is found on the side of the glucose test strip
For the lab experiment of mixing the diffusion and exposure solution, we are going to test if the pigment is released in the exposure solution. We used materials as follows: Obtaining a beet, we punched out 2 cm long beets using a cork borer. Then we wash the beets in running water, after that we prepared 10 test tubes each containing different pH solution.
...ond sets of data concluded that sucrose, glucose, and salt are hypotonic solutions that will remove water from a cell due to their tonicity. In the final part of the lab, results concluded that water potential moves along its concentration gradient (high to low) in an attempt to maintain equilibrium. It was determined that the orange and green solutions were hypotonic as they added water to the cells, whereas the blue, red, purple and yellow solutions were hypertonic as they sucked water from the cells.
Investigation of the Concentration and the Effect of Sucrose on Osmosis in Apple and Potato Tissues
Osmosis Investigation What is Osmosis? Osmosis is basically the movement of water molecules from a dilute system solution to a concentrated solution, through a partially permeable membrane. Water molecules are able to pass through the cell membrane because they diffuse whereas sugar molecules are larger and cannot diffuse as easily therefore not being able to pass through. Cell membranes are like visking tubes because they will let some substances through but not others. They are partially permeable membranes.
Osmosis Investigation Aim What happens to the mass of a raisin when you put it onto different sugar solutions. A sugar solution made from glucose and water. A raisin is a dried grape. The sand is a grape. A sugar solution is inside a grape.
I will only change the concentration of the solution as my aim is to find out how the concentration of sucrose solution affects osmosis.
Analyze each fraction by spotting 10 times with capillary tubes on a TLC plate, which is exposed to iodine vapor for 15 minutes.
In life, it is critical to understand what substances can permeate the cell membrane. This is important because the substances that are able to permeate the cell membrane can be necessary for the cell to function. Likewise, it is important to have a semi-permeable membrane in the cell due to the fact that it can help guard against harmful items that want to enter the cell. In addition, it is critical to understand how water moves through the cell through osmosis because if solute concentration is unregulated, net osmosis can occur outside or inside the cell, causing issues such as plasmolysis and cytolysis. The plasma membrane of a cell can be modeled various ways, but dialysis tubing is especially helpful to model what substances will diffuse or be transported out of a cell membrane. The experiment seeks to expose what substances would be permeable to the cell membrane through the use of dialysis tubing, starch, glucose, salt, and various solute indicators. However, before analyzing which of the solutes (starch, glucose, and salt) is likely to pass through the membrane, it is critical to understand how the dialysis tubing compares to the cell membrane.
I blended on high to make the potatoes more liquid-like. I grabbed the cheesecloth and placed on the top of the blender. I poured the potato extract on the container and labeled it. I found out that I have to make 1% sugar solution so I grabbed the sugar and measured into 5 grams on the scale. I added 5 grams of sugar on 250 ml graduated cylinder and poured the water into the cylinder. I mixed the sugar with water and poured it into the saucepan. I refilled the water into the graduated cylinder and poured into the saucepan. I turned on the heat of the stove and saw the sugar dissolved. I poured into a container and labeled 1% sugar solution. I repeated the same thing with 1% salt solution by using 1 gram of salt and filled the water into graduated cylinder by 100 ml. I answered question three. In the first experiment, I grabbed four transfer pipets and used it to put solutions into the test tubes by 3ml. I labeled it and placed into the plastic cups so it can stand upright. I grabbed each test tube and poured 2 ml of catalase solution into it. I also tapped and swirled to measure the bubbles by using the ruler. I wrote the numbers into the lab report. In the second experiment, I labeled the room
Activity 3: Investigating Osmosis and Diffusion Through Nonliving Membranes. In this activity, through the use of dialysis sacs and varying concentrations of solutions, the movement of water and solutes will be observed through a semipermeable membrane. The gradients at which the solutes NaCl and glucose diffuse is unproportional to any other molecule, therefore they will proceed down their own gradients. However, the same is not true for water, whose concentration gradient is affected by solute ...
When doing this experiment I was able to see the effect of different concentrations on the rate of osmosis, each was done by measuring the initial mass and length of the potato cylinder and after osmosis, the results were conducted to show that as the sucrose concentration increases the rate of osmosis also increases as I said in my hypothesis thusly making a direct decrease in mass.
The purpose of this experiment is to use our knowledge from previous experiments to determine the exact concentration of a 0.1M sodium hydroxide solution by titration (Lab Guide pg.141).