CELL MEMBRANE FUNCTION
Marisela Camacho Legarreta
June 30, 2013
ACTIVITY 1
INTRODUCTION
Be aware that all molecules have kinetic energy, which means that is an active energy that is always in motion. Molecules move in all different ways and this create an evenly distributed movement which is best known as diffusion. Diffusion is the movement of molecules from a region of their higher concentration to a lower concentration.
METHODS
Check the reaction of different compounds with the dialysis membranes and the deionized water in order to see if the compounds present diffusion and at what rate.
RESULTS
DISCUSSION 1. Describe two variables that affect the rate of diffusion.
The composition of the layer because this varies in every tissue, and the size of the molecule because the larger the molecule the slower the rate diffusion.
2. Why do you think the urea was not able to diffuse through the 20 MWCO membrane? How well did the results compare with your prediction?
The urea was not diffused in the 20 MWCO because the poles of the membrane are smaller than the urea’s molecules. This agreed with my predictions because after all the urea wasn’t able to diffuse in the 20 MWCO substance.
3. Describe the results of the attempts to diffuse glucose and albumin through the 200 MWCO membrane. How well did the results compare with your prediction?
Glucose was diffused in the 200 MWCO membrane, but albumin wasn’t, this is because the weight difference in this two molecules. This agreed with my predictions because glucose was the only one that diffused in the 200 MWCO.
ACTIVITY 2
INTRODUCTION
In this experiment we will observe how some molecules are not soluble in lipids because they are too large to go through the pores of the plasma membrane of the cell. When this situation is present, the molecules are able to solve thanks to a process called facilitated diffusion. This process relies on carrier proteins