Diffusion of Food Coloring Through Gelatin: A Model for Diffusion of Nano scale Medicine through Cells
Diffusion is the process by which molecules spread from areas of high concentration, to areas of low concentration. Diffusion can be observed by adding a few drops of food colouring to a glass of water. The scent from an open bottle of perfume quickly permeates a room because of random motion of the vapour molecules. A spoonful of salt placed in a bowl of water will eventually spread throughout the water. These are all good examples of diffusion and how it happens (Webster, 2014)
There are multiple molecules that can pass across cellular membranes freely. The cells that can easily across the lipid bilayer and enter the cell are small molecules and nonpolar molecules. Diffusion is the process that causes these molecules to move in or out of the cell. On average when more molecules randomly enter the cell than leave the cell this means the concentration of the molecule is greater outside the cell than inside. It is driven by random movements of individual molecules in the solution. Molecules that are capable of diffusion across a cellular membrane will eventually reach equal concentrations inside and outside of the cell. At this point the rate at which individual molecules enter and leave will be equal. (Highered.mcgraw-hill.com, 2014)
Aim: To investigate the particle size on the rate of diffusion
Purpose: The purpose of this lab is to observe the effect of particle size on the rate of diffusion. This activity is used to model the delivery of nanoscale medicines to organs, tissues and cells in the human body.
Hypothesis: If four different colors of food coloring are injected on the outside of three different gelatin disks, their rates of diffusion will be the different due to the fact of the different properties involved in the dye.
That diffusion will happen faster with the red die due to the properties of the substances in the dye.
4 sets of petri dishes (9cm diameters)
Food dye (red, blue, yellow, orange)
Three 10ml syringes
Graduated cylinders for measuring water
Plastic cups for dye solutions
A ring stand used to establish a “camera station”
Making the gelatin:
1. Obtain a non-reactive, non-stick baking pan/cookie sheet.
2. Get the cups and fill with water to fill so the water is 1 cm deep.
3. Add 2 envelopes of plain gelatin for every 1 cup or 200 mL of cold water. Microwave for 90 seconds.
4. Pour the gelatin solution into pan. Let set in refrigerator,
5. cut out and remove desired number of gelatin disks. Place in 9 cm petri dishes.
Mixing the Dye Solution:
1. Pour 16 mL of water into a plastic Dixie cup or beaker. Add 16 drops of red food dye and mix.
2. Repeat the steps above with yellow and blue food dye.
3. Pour 16 mL of water into a 4th Dixie cup. Add 8 drops of red dye and 8 drops of yellow dye to make 16 mL of orange solution.
Injecting the Dye Solution:
1. Using a clean 10 ml syringe, insert 16 mL of the dye solution (one color per dish) into the region