This is an interrupted case study that intersperses information about diffusion and osmosis with content review and knowledge application questions, as well as a simple experiment that can be conducted without the use of a laboratory. This case study is appropriate for use in undergraduate or high school general biology courses. The case begins with a narrative followed by a set of review questions used to introduce background information about diffusion and osmosis and define the terms active transport and passive transport. The second part of the case includes instructions for a simple experiment using gummy bears soaked in different solution to demonstrate osmosis that can be conducted by students at home or in a classroom. This is followed by an explanation of how the principles of diffusion and osmosis affect animal and plant cells. The case concludes with review questions and discussion of two other simple experiments that further demonstrate osmosis, one of which can be conducted by students at home.