If TI-82's are unavailable or foreign, data may be analyzed by hand. However, since math technology and science technology should be integrated whenever possible, it is worthwhile to expose students to instruments like graphing calculators. Students will be using the graphing calculator as well, so a basic working knowledge of that tool would be helpful. However, if the teacher is familiar with the calculator, students can be taught in just a few minutes how to do what needs to be done for this particular activity. Interest will be high, and extension opportunities will abound.
Preparation time is moderate .
Most solutions may be prepared will in advance and stored in the refrigerator. A suggestion is to make a large supply of stock sucrose solution and dilute it as necessary. Class time needed for this activity will be about two 50 minute periods, then an additional class period to compare, share, and integrate data. Activity Abstract Understanding concentration gradients is essential to understand life processes. Any time a cell has something move into or out of it, a gradient is either involved or created in the process.