I have always believed that science labs should not cost you an arm and a leg. I am privileged to work at a school with a significant lab equipment and materials budget. However, I know that many of you don’t. In this blog series, I will share some of my favorite labs that do not require special equipment and where most of the materials are available at your supermarket or that you could get for free.
Today I would like to share some easy and cheap labs and demos for teaching about cell membranes and cell transport.
Potato Osmosis
Potatoes are a must-have in a Biology classroom. They are perfect for showing osmosis in different solutions. You can easily prepare solutions with different salt or sugar concentrations and have students measure the change in mass of potato chips after a certain time. However, if you do not have access to a balance, they can measure the change in length. Depending on your group, you can take this further and have them calculate percentage change in mass or length.
Bubble Membrane Lab
This is one of my favorite labs. I mean, who doesn’t like to play with bubbles? I’ve found this great video on YouTube that goes through the setup and demonstrates the whole lab. Your students will remember this one!
Plasmolysis
If you have access to microscopes you can use red onions to show plasmolysis in cells. Just add some salt water to the onion cell slide and after a few minutes, you will be able to see the plasmolysis taking place. Furthermore, it is also easy to reverse by adding pure water to the slide.
Surface Area & Volume
Surface area to volume ratio is often a difficult concept for students to grasp. Becca over at Science Lessons That Rock explains how your students can investigate this using beetroot and bleach. I use this lab every year as it is so easy to set up.
Egg Osmosis
This is probably the most talked-about lab of the year! The students absolutely love it. The setup is easy and you have a lot of flexibility with solutions you will put your eggs in. Dissolving the shell is quite easy by leaving it in vinegar overnight. There are loads of different versions of this lab on the internet.
I hope you can use some of these ideas in your classroom. If you are looking for some notes on cell membranes, you can download this free cell membrane scribble note to use with your students.
