In this laboratory the students will investigate the processes of diffusion and osmosis in a model of a membrane system. They will also investigate the effect of solute concentration on water potential as it relates to living plant tissues.

Cells have particular structures that underlie their functions. Every cell is surrounded by a membrane that separates it from the outside world. Inside the cell is a concentrated mixture of thousands of different molecules which form a variety of specialized structures that carry out such cell functions as energy production, transport of molecules, waste disposal, synthesis of new molecules, and the storage of genetic material.

A basic understanding of diffusion and osmosis concepts is required.

This laboratory suggests that parts 1B and 1C be completed by all students. I have found that having all groups perform each sucrose dilution becomes quite cumbersome and time consuming. Most of us do not have this much equipment for several groups of students. I have assigned a concentration to each group and they use that concentration for both 1B and 1C. They then share their data with each other.

NA

None required but if computers are available, a graphing analysis program could be used to analyze the data.