Compare and contrast active and Passive transportation. You must include two ways they are alike and two ways?

Passive transport occurs when the concentration of something on one side of membrane is different from the concentration on the other side.  It occurs when that substance can pass through the membrane, and always in the direction of more -> less.  No energy is required to make the substance move; in fact, this movement generates energy.  This is like rolling a rock down a hill--it just does it on its own.

Active transport occurs in the opposite direction, from less -> more.  It requires energy for transport.  This is like rolling a rock up a hill--you have to push it the entire way!

Both involve the transport of a substance across a membrane, and the change in concentrations on different sides of a membrane.  Both are also important to the proper functioning of a cell.

Active transport requires energy, but passive transport requires none.

Active transport requires a special protein to make the transport occur, but passive transport requires none.