Diffusion and Osmosis Lab

The AP Biology students were tasked with a lab on the processes of osmosis and diffusion. 

Science: Students use what they have learned in AP Biology in terms of how cells transport water and solutes through their membranes

Technology:  Students were asked to create a time-lapse video to demonstrate the process of diffusion

Engineering:  Students created their own agar cubes and added an indicator so they could track a color change

M: Students calculated the Surface Area to Volume Ratio of their cubes

Students cut different sizes of agar gel to represent different surface area to volume ratios.  Those that were smaller have a higher surface area to volume ratio than large cubes. 

Students measure their different sized cubes to calculate the surface area to volume ratio, utilizing math skills.  

Students placed the agar cubes that have been treated with an indicator that turns magenta when treated with a base, but white when treated with an acid.  The cubes were first treated with a base to turn the initial magenta color. The solution consists of water and an acid.  The purpose is to see how quickly the acid diffuses through the agar cubes and changes the color.

Students cut potatoes into similar sizes.  The potato presentations a semipermeable membrane which will allow water through.  

5 sugar solutions have been made with different colors to keep them separate.  Each one is a different level of concentration of sugar.  

Students will place each potato in the cup and allow it to sit for a few minutes.  Then they weigh the potatoes afterwards to see how much water it absorbed.  They then decided if the solution was hypertonic, isotonic, or hypotonic.