Characteristics of carriermediated transport

- apply to facilitated diffusion and primary and secondary active transport:

1. Stereospecificity. For example, D-glucose (the natural isomer) is transported by facilitated diffusion, but the L-isomer is not. Simple diffusion, however, would not distinguish between the two isomers because it does not involve a carrier.

2. Saturation. The transport rate increases as the concentration of the solute increases, until the carriers are saturated. The transport maximum (Tm) is analogous to the maximum velocity (Vmax) in enzyme kinetics.

3. Competition. Structurally related solutes compete for transport sites on carrier molecules. For example, galactose is a competitive inhibitor of glucose transport in the small intestine.

Was this article helpful?

0 0
Anxiety and Depression 101

Anxiety and Depression 101

Everything you ever wanted to know about. We have been discussing depression and anxiety and how different information that is out on the market only seems to target one particular cure for these two common conditions that seem to walk hand in hand.

Get My Free Ebook

Post a comment