This is a resource you can use and adapt for all grades to teach students about cells. Specifically I used this resource to plan a lesson for fifth graders. This resource supplies sample worksheets, detailed labs, and fun activities. There are activities to create your own model cell and show how diffusion and osmosis work. Check out this resource to give your students a hands on experience with cells. URL below.
Cells! Osmosis, Diffusion, and Cell models