Question

Describe how proteins are used in active and passive transport. How do they differ?

Answer 1

In passive transport, molecules are moving from areas of high concentration to areas of low concentration. Examples: diffusion, osmosis (water). Protein channels and carriers are sometimes also involved in passive transport.

An example in "real life": when you spray a high concentration of perfume in the corner of a room, it will gradually diffuse to the rest of the room.
This requires no energy. Passive transport does not require ATP.

In active transport, molecules are moving from areas of low concentration to areas of high concentration. An example of this in our bodies is the sodium-potassium pump. There is a high concentration of potassium in our bodies and a lower concentration of potassium outside our bodies. This is why energy is required to keep bring potassium from outside our bodies to inside our bodies. This is called active transport, which requires ATP.

Answer 2

Also, passive diffusion doesn't require input of energy, which is a good thing to remember, especially when you're dealing with pharmaceutical agents, such as drugs, which need to enter the cell.