What are some of the factors that affect the rate of diffusion of ions through a solution?
Factors Affecting the Rate of Diffusion Size Small molecules can slip by the polar heads of the phospholipids and through the membrane to the other side. Oxygen gas, carbon dioxide and water can move in this manner. Very large molecules like proteins cannot diffuse across the membrane at all. Shape Glucose is able to get into cells much faster than other sugars. This is accomplished by facilitated diffusion. A carrier protein specific for glucose (not other sugars) combines with it on the outer surface, closes around it, and then opens to the inside of the cell where the glucose is released. The carrier then returns to its original shape and is ready to transport another glucose molecule. These carriers can move up to 100 glucose molecules per second across the cell membrane. Concentration The greater the concentration gradient between the outside and inside of the membrane the greater the rate of diffusion. If the concentration of oxygen outside the cell increases then it will diffuse
