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Monday, August 19, 2019
Diffusion Essay -- essays research papers
Lab Report #1: Diffusion Introduction: The human body undergoes a variety of processes throughout each and every day in order to sustain life. Tasks such as walking, breathing, and digesting what has been eaten are sometimes considered mundane, even taken for granted. One such process that is necessary to maintain life is diffusion. Diffusion is a key factor in moving ions, fuels, and other molecules into and out of the blood. It is one of the most important components in supplying oxygen to the alveoli and removing carbon dioxide. Without diffusion, substances would find it very difficult to pass through membranes and could cause detrimental effects to the human body. The paradox scientists have drawn is related to glucose molecules and the directions in which the molecules â€Å"know†to move. No single molecule should diffuse in any particular fashion, but should diffuse randomly. This report looks at four simulations attempting to solve the problem presented, how do the molecules know which way to diffuse? In order to understand the obtained research, it is necessary to present and identify the key components of Fick’s Law of Diffusion: F = -D * A*dC/dx F = the flow of material across a real or imaginary plane D = the diffusivity of the diffusing molecules (the ease in which the molecule diffuses in the surrounding medium)                          A= area of the plane                          C= concentration of the molecules                          X= distance                          dC/dx = the concentration gradient There will be four simulations conducted in order to apply Fick’s Law and determine if molecules do in fact know which way to diffuse. The first simulation will look at a single molecule in an open area, the second looks at the movement of several molecules, the third looks at molecules diffusing in a ... ...te the change in concentration with respect to the change in distance.      In Simulation 4 we have two chambers connected with a pipe. Like simulation 2, the concentration of molecules across the whole system at equilibrium is equally distributed. If the dimensions of the pipe were small and narrow, only a small percentage of the molecules will be contained in the pipe at equilibrium. The flow of molecules to the right chamber would decrease. The calculation of the rate of approach to equilibrium in simulation 2 cannot be applied here because we have a pipe of a different volume that alters the flow. As the figure above depicts, the rate of approach to equilibrium increase as the diameter of the pipe increases. However the rate of approach will not increase infinitely but will plateau as some point because the diameter of the pipe can only be so large to connect the boxes. Accordingly, increasing the length of the pipe will slower the rate of approach to equilibrium because the molecules will have to travel a greater distance. References â€Å"Diffusion- Simulation of randomly moving particles†WebCT. Drexel University. April 2005
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