1. Diffusion and Osmosis, June 4, 2013
2. Purpose: The purpose of this laboratory is to help provide visual understanding of diffusion which is a service of high concentration spontaneously (no energy required) moving to an area of low concentration. Likewise having a look at osmosis, which is the motion of chemicals throughout the cell membrane.
Osmosis needs some kind of energy to be put in for this to take place. After these experiments we should have a much better idea and visualization of how chemicals move across the cell membrane.
Dropper bottle of water
Substance microscopic lense
Slide and coverslip
3 test tubes
2 400 ml beaker
30 cm damp dialysis tubing
I2KI option starch solution
30% glucose solution
String or rubber band
Test tube rack
Slides and cover plates
4. Techniques and Procedures:
Prepare a slide of dry carmine and water and cover slip Put under the microscope, take a look at under the different magnifications, record you findings to later on set up your conclusion.
Experiment 2: Usage dialysis tubing that has been taking in water, fold it “accordion style” and use string to close completions like a bag. Roll opposite end of bag till it opens and add 4 pipettes of 30% glucose into it. Add 4 pipettes of starch option into it.
Mix contents with bag closed. Then rinse with faucet water. Include 300 mL of water to a 400- to 500- ml. add a few drops of service till it turns an amber-yellow color. Leave bag in beaker for thirty minutes.
Get rid of bag then let it dry.
Obtain 7 equal size bore hole cylinder from the potato, cut roughly to the exact same size record the length and weight of each ensuring they remain order. Next is to collect 7 cups filled with 100 ml of the 6 various concentrations of glucose (, 0.1 0.2, 0.3, 0.4, 0.5, 0.6, and water). Record the time and submerge the potato cylinders in the solutions. Let them sit for an hour and half prior to getting rid of, weighting and tape-recording the final weight.
5. Observations and data:
Carmine powder observation: movement is random, looks like continuous vibrations Experiment 2:
Test final color
Before heat of Benedicts test
After heat Final Color
After letting the bag sit inside the bath for 30 minutes the solution inside the bag went from a clear color to a slight yellow color. And after the final results of benedicts test I can conclude the carbohydrates did move from inside the bag out.
My observation concerning the size of the potato cylinder in the glucose decreased as the concentration of glucose increased and the potato in water remained the same size. 6. Conclusion:
The carmine powder experiment proved the theory of diffusion because with no energy required you can see the movement of particles under a microscope. Again diffusion is the movement of molecules from high concentration to low concentration with no energy required. On the other hand the experiment concerning osmosis were the dialysis bag and the saturation of the potato. Both experiments demonstrated the movement of sugar or water across a cell membrane. On the dialysis bag experiment we could see the slight color change as the IKI did move across the membrane in to the bag but the big surprise was see that after the benedicts test how strong the sugar content was in the beaker solution.
Lastly the potato experiment demonstrated through the change in weight how water could pass through the membrane. As we saw the greater concentration of glucose the more shriveled the potato got, indicating the water inside the potato exited out trying to make the concentration equal. The solution containing strictly water made the potato swell as if the concentration inside was lower than the concentration outside.
Cite this essay
Lab 4 Diffusion and Osmosis. (2016, Apr 17). Retrieved from https://studymoose.com/lab-4-diffusion-and-osmosis-essay