Fluid Mosaic Model

Objective– The objective of this project is to build a Fluid mosaic model of a cell membrane and to investigate the regulation of a cell membrane as to how the fluids move in and out of the membrane.

The cell membrane is a kind of barrier which separates the cell from its external environment. It also controls the passage of all the materials coming in and going out of the cell. This membrane comprises of double layer having phospholipids, which is called as the lipid bilayer. Placed between these phospholipids are the other various molecules like protein channels, cholesterol, pumps, and the carbohydrate chains. With all the cooperation of these phospholipids and also the other molecules the passage of these molecules in and out of the cell is how it is controlled.

Requirements–

• 3 pipe cleaners of different colors
• Thick and medium-size rubber band
• Drinking straw of regular-sized
• 50 or more cotton swabs
• 1 marble
• Scissors
• 1 BB

Procedure–

1. Gather all the cotton swabs in the form of a bundle and then place rubber band in the middle in order to keep in the form of bundle.
2. Place an receptor molecule in the cell membrane.
   • Taking one of pipe cleaners, and place it through bundle of the cotton swabs.
   • Bend the one end of it into a circular shape. It represents as to how the signal molecule binds to the specific molecule. Only the circular-shaped molecule will be able to bind with the receptor.
3. Use second pipe cleaner as an carbohydrate chain. Then place inside the bundle of the cotton swabs in a similar manner as that of the step 2. Don’t bend the pipe cleaner.
4. Cut the drinking straw in two halves. Place each of the halve into various locations within the bundle of the cotton swabs. These things represent as the pumps and protein channels
5. Hold the cotton swabs in vertical position and place marble on the top of swabs. Check whether it passes between the swabs?
6. Later place marble on the top of straw. See whether it passes through the straw?
7. Still by holding the swabs vertical way, place BB on the top of the cotton swabs. Does this passes between the swabs?
8. Then place BB on the top of straw. Check whether it passes.
9. Keep your mouth on the end of the cotton swabs and then blow. Can you feel the air on other side of swabs?

The result of the experiment will explain you how the cotton swabs and the straws actually represents the components of an real cell membrane.