4.2: Diffusion and Osmosis (Instructor Materials Preparation)
- Page ID
- 34830
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This is the prep for one section of 24 students.
Part 1: Brownian Motion
Students will do this part individually.
| Materials | Quantity | Notes |
|---|---|---|
| Microscope slides | 1 per student | Also used in Part 3 |
| Coverslips | 1 per student | Also used in Part 3 |
| Water dropper bottles | 1 per table | |
| Carmine red powder | 2 small watch glasses | On side counter |
Part 2: Diffusion across a Semipermeable Membrane
Students will do this part in table teams.
| Materials | Quantity | Notes |
|---|---|---|
| Beakers (400 mL) | 2 per table | |
| Wax pencil | 1 per table | |
| Dental floss or thread | 1 per table | |
| Dialysis tubing | 2 per table | |
| Phenolphthalein | 1 per table | Dropper bottle—does not go down drain! |
| 1 M NaOH (sodium hydroxide) | 1 per table | Dropper bottle |
| Iodine (I2KI) | 1 per table | Dropper bottle |
| 1% starch solution | ~10mL per table | On side counter |
| Pipette/pipettor setup for starch (10 ml) | 2 per class | On side counter—specifically for starch |
| Pipette/pipettor set up | 1–2 per table | |
| Large waste bucket for starch | 1–2 per class |
Part 3: Osmosis and the Cell Membrane
Students will do this part individually.
| Materials | Quantity | Notes |
|---|---|---|
| Elodea | 2 bowls | On side counter |
| Forceps | 2 pairs per bowl | |
| 5% NaCl solution | 1 per table | Dropper bottle |
| Slidewash bowls | 1–2 per room |
Part 4: Experimental Design
Students will do this part in pairs.
| Materials | Quantity | Notes |
|---|---|---|
| 2% agar plates | 2 per table | Use deep petri dishes for diffusion experiment |
| Clear plastic rulers | 2 per table | |
| Potassium permanganate | 1 per table | Dropper bottle |
| Methylene blue | 1 per table | Dropper bottle |
| Cork borers | 2–3 sets | On side table |
Contributors and Attributions
- Biology Labs. Authored by: Wendy Riggs. Provided by: College of the Redwood. Located at: www.redwoods.edu. License: CC BY: Attribution