
Active Transport - Energy to Transport

Proteins in the Membrane

Many times, proteins have to work against a concentration gradient. That term means they are pumping something (usually ions) from areas of lower to higher concentration. This happens a lot in neurons. The membrane proteins are constantly pumping ions in and out to get the membrane of the neuron ready to transmit electrical impulses.
Stopping the Transport

Imagine that you are a cell and have ten proteins working to pump calcium into the cell. What if a poison came along and blocked eight of them? You could not survive with just two pumps working and would slowly die. It would be like expecting you to breathe with your mouth and nose plugged up.
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Related Video...
Active and Passive Transport (Johnson County College Video)
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