Passive Transport
Passive Transport

Passive Transport

Author: Nathan Lampson
This lesson introduces the process of passive transport, explaining that it is a form of transport that does not require energy, and moves molecules down their concentration gradient.
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Particles tend to spread out evenly in an available space.  Passive Transport is when molecules spread out over an availabe space by moving through a permeable membrane.

When molecules move down a concentration gradient through a membrane, no energy is used.


Oxygen enters our blood stream and carbon dioxide escapes by using passive transport.


Image: Osmosis is a form of passive transport. There are 9 water molecules on the right side of the membrane (high concentration) and 6 water molecules on the left side of the membrane (low concentration). In Passive Transport, molecules move from high concentration to low concentration across a membrane.