Surfactant is an essential component for the respiratory system to function properly. Knowing the physiology of surfactant in the alveoli is important to know when learning the structure of the air sacs and how they work. This experiment is designed to make the understanding of surfactant in the alveolar film easier to learn, because it's not very simple. Surfactant is a detergent-like substance produced by the Type II alveolar cells in the walls of the alveoli. Surfactant is produced to reduce the surface tension of the water molecules that primarily compose the walls of the alveoli. For this experiment, we will be using milk and food coloring to represent the water (milk) and gas (food coloring) in the respiratory system, as seen in the liquid-gas boundary of the alveolar wall (water) and its volume (gas). We will place the milk in a shallow dish so that it completely covers the bottom of the dish. Drops of food coloring are going to be added into the milk at the center of the dish, and then observed. Drops of liquid dishwashing soap, representing surfactant, are then added to the center as well. Once the soap drops are added we will observe what changes happen to the food coloring and milk. Because I know milk is non-polar and food coloring is polar, my hypothesis predicts the two will not mix voluntarily at first, but the soap acting as a surfactant, when added, will help the two liquids mix together.
Materials and Methods
For this experiment, I used a 16oz milk, 4 different color food coloring bottles, liquid hand soap, and a small clear dish with approximately 5 inches in diameter. I placed the dish in a flat steady surface. I then poured the milk making sure the whole bottom of the dish is covered and still remained shallow. Next, I added about four drops of food coloring to the milk at the center of the dish. Lastly, I added about four drops of the liquid hand soap in the same exact place where I had added the...