Assignment: BIO201L Lab 4 Diffusion and Osmosis Paper
Assignment: BIO201L Lab 4 Diffusion and Osmosis Paper
Kit Code (located on the lid of your lab kit):AC-Q0N5WHE
Pre-Lab Questions:
”1. Compare and contrast diffusion and osmosis.”
Click here to enter text.
”2. What is the water potential of an open beaker containing pure water? ”
Click here to enter text.
”3. Why don’t red blood cells swell or shrink in blood? ”
Experiment 1: Diffusion through a Liquid
| Table 1: Rate of Diffusion in Corn Syrup | |||||
| Time (sec) | Blue Dye | Red Dye | Time (sec) | Blue Dye | Red Dye |
| 10 | 1.7 | 2.1 | 70 | 2.4 | 2.7 |
| 20 | 2.2 | 2.3 | 80 | 2.4 | 2.8 |
| 30 | 2.2 | 2.4 | 90 | 2.4 | 2.8 |
| 40 | 2.3 | 2.5 | 100 | 2.5 | 2.8 |
| 50 | 2.4 | 2.5 | 110 | 2.5 | 2.9 |
| 60 | 2.4 | 2.5 | 120 | 2.6 | 2.9 |
| Table 2: Speed of Diffusion of Different Molecular Weight Dyes | |||
| Structure | Molecular Weight | Total Distance Traveled (mm) | Speed of Diffusion (mm/hr)* |
| Blue Dye | Click here to enter text. | Click here to enter text. | /hr |
| Red Dye | Click here to enter text. | /hr |
”*Multiply the total distance diffused by 30 to get the hourly diffusion rate”
Post-Lab Questions
”1. Examine the plot below. How well does it match the data you took in Table 2?”
.
”2. Which dye diffused the fastest? ”
.
”3. How does the rate of diffusion correspond with the molecular weight of the dye? ”
Click here to enter text.
”4. Does the rate of diffusion change over time? Why or why not? ”
Click here to enter text.
Experiment 2: Diffusion – Concentration Gradients and Membrane Permeability
| Table 3: Indicator Reagent Data | ||||
| Indicator | Starch Positive
Control (Color) |
Starch Negative
Control (Color) |
Glucose Positive
Control (Color) |
Glucose Negative
Control (Color) |
| IKI Solution | Click here to enter text. | Click here to enter text. | n/a | n/a |
| Glucose Test Strip | n/a | n/a | Click here to enter text. |
| Table 4: Diffusion of Starch and Glucose Over Time | ||
| Indicator | Dialysis Bag After 1 Hour | Beaker Water After 1 Hour |
| IKI Solution | Click here to enter text. | Click here to enter text. |
| Glucose Test Strip | Click here to enter text. | Click here to enter text. |
Post-Lab Questions
”1. Why is it necessary to have positive and negative controls in this experiment? ”
Click here to enter text.”2. Which substance(s) crossed the dialysis membrane? Support your response with data-based evidence.”
Click here to enter text.
”3. Which molecules remained inside of the dialysis bag? ”
Click here to enter text.
”4. Did all of the molecules diffuse out of the bag into the beaker? Why or why not? ”
Click here to enter text.
ORDER CUSTOMIZED PAPERS AT 5% DISCOUNT NOW
Experiment 3: Osmosis – Direction and Concentration Gradients
”Hypothesis: ”Click here to enter text.
| Table 6: Sucrose Concentration vs. Tubing Permeability | ||||
| Band Color | Sucrose % | Initial Volume (mL) | Final Volume (mL) | Net Displacement (mL) |
| Yellow | Click here to enter text. | Click here to enter text. | Click here to enter text. | Click here to enter text. |
| Red | Click here to enter text. | Click here to enter text. | Click here to enter text. | Click here to enter text. |
| Blue | Click here to enter text. | Click here to enter text. | Click here to enter text. | Click here to enter text. |
| Green | Click here to enter text. | Click here to enter text. | Click here to enter text. | Click here to enter text. |
Post-Lab Questions
”1. For each of the tubing pieces, identify whether the solution inside was hypotonic, hypertonic, or isotonic in comparison to the beaker solution it was placed in. ”
Click here to enter text.
”2. Which tubing increased the most in volume? Why? ”
Click here to enter text.
”3. What does this tell you about the relative tonicity between the contents of the tubing and the solution in the beaker? ”
Click here to enter text.
”4. What would happen if the tubing with the yellow band was placed in a beaker of distilled water? ”
Click here to enter text.
”5. Osmosis is how excess salts that accumulate in cells are transferred to the blood stream so they can be removed from the body. Explain how this process works in terms of tonicity. ”
Click here to enter text.
”6. How is this experiment similar to the way a cell membrane works in the body? How is it different? Be specific with your response. ”
Click here to enter text.
”7. If you wanted water to flow out of a tubing piece filled with a 50% solution, what would the minimum concentration of the beaker solution need to be? Explain your answer using scientific evidence. ”
Click here to enter text.
Experiment 4: Osmosis – Tonicity and the Plant Cell
| Table 7: Water Displacement per Potato Sample | |||||
| Potato Type | Potato Observations | Sample | Initial Displacement (mL) | Final Displacement (mL) – Step 11 | Net Displacement (mL) |
| Click here to enter text. | Click here to enter text. | A | Click here to enter text. | Click here to enter text. | Click here to enter text. |
| Click here to enter text. | Click here to enter text. | B | Click here to enter text. | Click here to enter text. | Click here to enter text. |
| Click here to enter text. | Click here to enter text. | A | Click here to enter text. | Click here to enter text. | Click here to enter text. |
| Click here to enter text. | Click here to enter text. | B | Click here to enter text. | Click here to enter text. | Click here to enter text. |
Post-Lab Questions
”1. How did the physical characteristics of the potato vary before and after the experiment? Did it vary by potato type? ”
Click here to enter text.
”2. What does the net change in the potato sample indicate? ”
Click here to enter text.
”3. Different types of potatoes have varying natural sugar concentrations. Explain how this may influence the water potential of each type of potato. ”
”4. Based on the data from this experiment, hypothesize which potato has the highest natural sugar concentration. Explain your reasoning. ”
”5. Did water flow in or out of the plant cells (potato cells) in each of the samples examined? How do you know this? ”
Click here to enter text.
”6. Would this experiment work with other plant cells? What about with animal cells? Why or why not? ”
Click here to enter text.
”7. From what you know of tonicity, what can you say about the plant cells and the solutions in the test tubes? ”
Click here to enter text.
”8. What do your results show about the concentration of the cytoplasm in the potato cells at the start of the experiment? ”
Click here to enter text.
”9. If the potato is allowed to dehydrate by sitting in open air, would the potato cells be more likely to absorb more or less water? Explain. ”
Click here to enter text.