How the physical gradients generated by the Active Transport maintain the Passive Transport ?
Thank you for your help :)
- JimLv 74 weeks ago
Passive transport is a great strategy for moving molecules into or out of a cell. It's cheap, it's easy, and all the cell has to do is sit there and let the molecules diffuse in. But...it also doesn't work in every situation. For instance, suppose the sugar glucose is more concentrated inside of a cell than outside. If the cell needs more sugar to meet its metabolic needs, how can it get that sugar in?
Here, the cell can't import glucose for free using diffusion, because the natural tendency of the glucose will be to diffuse out rather than flowing in. Instead, the cell must bring in more glucose molecules via active transport. With active transport, unlike passive transport, the cell expends energy (for example, in the form of ATP) to move a substance against its concentration gradient.