There are probably many opinions about what makes a relationship work...being in love with someone gets the ball rolling, but it's said that love is what keeps it moving. I have discovered that in order to have a successful happy relationship, you have to have a little of both.
There are three main types of Active Transport: The Sodium-Potassium pump, Exocytosis, and Endocytosis. The Sodium-Potassium Pump is a structure known as a cell-membrane pump that uses energy to transport Sodium and Potassium ions in and out of the cell.
The action of the sodium-potassium pump is an example of primary active transport. The two carrier proteins on the left are using ATP to move sodium out of the cell against the concentration gradient. The proteins on the right are using secondary active transport to move potassium into the cell. Active transport is the movement of a substance across a membrane against its concentration gradient.