Passive Transport
Passive Transport is any method of transporting materials that does not use energy. Because of this, it is generally only found when particles move down their concentration gradient, from an area of higher concentration to an area of lower concentration. One of the most common types of Passive Transport is Osmosis, which is solely responsible for moving water through a cell's membrane. Other kinds of particles can also move through the cell membrane as well. They are usually very small molecules such as oxygen and simply pass between the spaces in the lipid bilayer of a cell's membrane. Passive Transport really isn't a very complicated process and as such is fairly easy to understand. However, it is a vital process that all cells need to survive.
Active transport, on the other hand, requires energy to function. This energy is usually provided in the form of ADP or ATP, types of sugar molecules produced in cells from more complex sugars. As mentioned before, Active Transport is usually used to move atoms or molecules UP the concentration gradient, as in from an area of lower concentration to an are of higher concentration.
See Also:
-Osmosis
-Active Transport
Active transport, on the other hand, requires energy to function. This energy is usually provided in the form of ADP or ATP, types of sugar molecules produced in cells from more complex sugars. As mentioned before, Active Transport is usually used to move atoms or molecules UP the concentration gradient, as in from an area of lower concentration to an are of higher concentration.
See Also:
-Osmosis
-Active Transport
Facilitated Diffusion; Image in Public Domain