Cell Membranes: Diffusion and Osmosis


Create a model cell to observe diffusion through a membrane.

What molecules can pass through the pores of a cell membrane? Create a model cell and perform tests to determine what molecules diffused into or out of your model cell.

How does osmosis (diffusion of water) affect plant and animal cells placed in different environments?

  • Predict what molecules might pass through the cell model membrane.
  • Perform lab tests to determine if your predictions are correct.
  • Observe what happens when plant cells are placed in environments that have different salt concentrations.
  • Explain how diffusion and osmosis can be applied to real-world scenarios.
Assembled kits
Materials to assemble 10 kits - includes all supplies, printed labels, and student instructions copy master
Materials to refill 10 kits

Kit Includes

  • Student instructions
  • Dialysis tubing
  • 1 starch packing peanut
  • 1 plastic cup
  • 1 small measuring cup
  • 1 tube of simulated “Glucose”
  • 1 strip of simulated “Glucose Indicator Paper”
  • Iodine
  • 1 stirrer
  • 1 dropper
  • Osmosis and Red Onion Cells graphics sheet

Also Required

  • Warm water
  • Safety goggles

Quantity Discounts


  • 1 – 9 kits: $14.95 each
  • 10 – 24 kits: $14.20 each
  • 25+ kits: $13.46 each


  • 1 – 9 packs: $90.95 each
  • 10+ packs: $86.40 each


  • 1 – 9 packs: $33.95 each
  • 10+ packs: $32.25 each

Correlation to Next Generation Science Standards (NGSS) Shop by NGSS »

Performance Expectations:

MS-LS1-2. Develop and use a model to describe the function of a cell as a whole and ways parts of cells contribute to the function.

  • Science & Engineering Practices

    Developing and Using Models - Develop and use a model to describe phenomena.

  • Disciplinary Core Ideas

    LS1.A: Structure and Function - Within cells, special structures are responsible for particular functions, and the cell membrane forms the boundary that controls what enters and leaves the cell.

  • Crosscutting Concepts

    Structure and Function - Complex and microscopic structures and systems can be visualized, modeled, and used to describe how their function depends on the relationships among its parts, therefore complex natural structures/systems can be analyzed to determine how they function.