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cabinet Membranes Problem set

difficulty 7: Diffusion

Tutorial to help answer the question


Crossing a membrane by straightforward diffusion can be identified from facilitated diffusion because:

A.
Simple diffusion does not call for energy: helped with diffusion calls for a source of ATP.

You are watching: How are simple diffusion and facilitated diffusion similar

B. Simple diffusion deserve to only move product in the direction of a concentration gradient; facilitated diffusion moves products with and against a concentration gradient.
C. Simple diffusion is no saturable; facilitated diffusion prices are limited by the number of functional membrane proteins and can it is in saturated*
D. Simple diffusion is discovered only in prokaryotes while facilitated diffusion is found only in eukaryotes.

Tutorial

Diffusion

Diffusion means that the net movement of particles (molecules) is native an area of high concentration to low concentration.
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If the particles deserve to move v the lipid bilayer by simple diffusion, climate there is no limit to the number that have the right to fit v the membrane. The price of diffusion boosts linearly as we add much more particles to one side of the membrane.

If the particles deserve to only pass through protein channels, then the rate of diffusion is determined by the variety of channels and the number of particles.

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Once the networks operate at their maximal rate, a more increase in fragment numbers no longer increases the noticeable rate of diffusion. In ~ this restricted rate we explain the protein channel together being saturated.

The cartoon illustrates number of points about facilitated diffusion. The corpuscle are much more concentrated top top one next of the membrane, and yet they can move in both directions. However, the net movement is from high fragment concentration to low. If the number of particles gets so high top top one next of the membrane the they interfere v diffusion v the protein channel, then us observe a limit to the price of diffusion in ~ the allude of saturation.


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animation used with permission of the virtual Cell web Page
Problem 7 | prize | difficulty 8

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