Osmosis, the movement of a solvent (usually water) across a semi-permeable membrane from an area of higher solvent concentration to an area of lower solvent concentration, is key in the maintenance of homeostasis. This demo shows osmosis across a semi-permeable membrane.
In this demo, a polyethylene strip is charged by rubbing with wool. The strip is then used to test what happens to the flow of charge when the strip is placed in contact with a conductor (iron nail)... read more
Categories: Teacher Demonstration
Proteins have specific uses inside cells to support biochemical reactions important for cell structures and metabolic processes. Cells maintain a balanced internal environment that allows these... read more
Students watch the teacher demonstrate the OJ powered clock. The teacher guides students to wonder what they could change to make the clock work. They do some brainstorming and then the next period,... read more