How Does The Concentration Affect The Rate Of Diffusion

Diffusion is the movement of particles from an area of higher concentration to an area of lower concentration. Because of the selective permeability of the membrane only water and other very small particles (iodine) can be diffused through simple diffusion. The solution out of the dialysis tubing had a higher distelled iodine concentration of solutes (iodine + H2O) than did the starch solution. So iodine move into the cell and react with starch molecules to formed starchiodine, the blue compound, with a specific rate. The test show that mean rates of diffusion are significantly different acording to the concentration. So the concentration have an impact on the rate of diffusion. Also, the difference between the concentration in each compartment, concentration gradient. We see in the Fick law that if you modulate C1-C2 you will have
The cell membrane is similar to the dialysis tubing, so the cell would absorb molecules because of the concentration gradient if it were placed in an environment in which interested molecule concentration is greater than that of the cell. If it's reverse molecules will move out of cells, it's an essential process to survive. We know that diffusion occurs in the respiratory system to keep absorbing oxygen used by organs for exemple. ''Oxygen constantly diffuses into the blood from the alveoli, but the blood is immediately replaced with more deoxygenated blood, maintaining a steep concentration gradient. Similarly carbon dioxide diffuses down a concentration gradient from the blood into the alveoli'' (see the 19/09/2015 from http://www.abpischools.org.uk/page/modules/breathingandasthma/asthma4.cfm?coSiteNavigation_allTopic=1). Without maintaining the concentration gradient of oxygen and carbon dioxide here organisms died. That can occur with also bigger molecules, charged molecules. For exemple, absorption of glucose in gastrointestinal truct or movement of Na+ and K+ in the nervous