How does facilitated diffusion occur

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Interpretation: By graphing this equation, we see that at low concentrations of solute, the rate of diffusion into a cell occurs almost linearly, like simple diffusion.

Notice that at low solute concentrations, the slope is much steeper than that of simple diffusion. Facilitated diffusion can increase the rate of diffusion of particular molecules at low concentrations.

However, the rate of facilitated diffusion levels off with increasing solute concentration. Additional increases in external solute concentration cannot increase the rate of diffusion once carrier proteins are saturated. Conclusion: Passive diffusion of solute into a cell is linearly related to the concentration of solute outside the cell.

Carrier proteins increase the rate of diffusion by allowing more solute to enter the cell. Facilitated diffusion, however, approaches a maximum rate as the carrier proteins become saturated with solute.

What is the slope of this line? What do increases or decreases in the slope mean biologically? Now assume the concentration gradient is a constant.

Look at the equation for facilitated diffusion and find the horizontal asymptote. Try graphing this equation with different values for K. How does this change the concentration at which the carrier proteins are saturated? Simple diffusion can only move material in the direction of a concentration gradient; facilitated diffusion moves materials with and against a concentration gradient. Simple diffusion is found only in prokaryotes while facilitated diffusion is found only in eukaryotes.

Tutorial Diffusion Diffusion means that the net movement of particles molecules is from an area of high concentration to low concentration. Problem 7 Answer Problem 8. Diffusion means that the net movement of particles molecules is from an area of high concentration to low concentration.