Diffusion and Osmosis

Brumfield 1

Bria Brumfield

Kimberly Mason/Dr. Gordon

Lab Report I

11 October 2012

Diffusion

Introduction: In chapter five, the topic of diffusion was bought up. There are many different types of diffusion, the first one being simple diffusion. Simple diffusion is the movement of molecules along a concentration gradient from an area of high concentration to an area of lower concentration. Osmosis is another type of diffusion. Osmosis is simple the diffusion of water through a selectively permeable membrane from an area with high concentration of water to an area with lower concentration of water. The last and final type of diffusion is called facilitated diffusion. Facilitated diffusion is when molecules are passed across the cell membrane by transporter proteins. The assignment was to design your own experiment asking a question about membrane transport. The question me and my partner Sabrika chose was “what is the effect of temperature on the movement of sodium chloride across a membrane. Our hypothesis was the higher the temperature, the less the bag will begin to weigh

Materials and Methods: The materials we used in order to start our experiment were, dialysis tubing, sodium chloride, water and heat bath and a scale. We had three different water filled tubes, then we placed the sodium chloride that was in the dialysis tube into the water. We left one at room temperature, one in 45 degrees Celsius and the last one at 100 degrees Celsius. We monitored these for 10 minutes checking the weight every two minutes. My partner and I rotated keeping track of the weight and recording the information.

Results: Instead of losing mass in higher heat, some actually gained weight. When placed in heat, the sodium chloride gained weight the longer they were left in the heat bath. All of the tubes started off at about the same weight, however at the end of the ten minutes, tube A (RT) was left to weigh 45.2 grams. The tube that was set at a 45 degreed Celsius ended...