Diffusion, Osmosis and Active Transport .... What YOU Need to Know :)

Well hi there Mr. Landry's sophomores! :) So, I hear you guys will be learning all about diffusion, osmosis and active transport. Lucky for you, you guys have great resources.... aka all of us and Mr. Landry and numerous other things. Anyways, let's get started :)

First off, let's cover diffusion. Diffusion is the tendency for molecules of any substance to spread out evenly. Diffusion can be broken down into two main subdivisions, simple diffusion and facilitated diffusion. In both cases, diffusion is simply the movement of particles from a HIGH to LOW concentration and NO energy is needed so it is called "passive transport". Where simple diffusion and facilitated diffusion differ is that simple diffusion does NOT need extra help. Facilitated diffusion NEEDS extra help - think of facilitated as "being watched over" sort of like a babysitter helping a kid with a project. In this case, facilitated diffusion is the movement of particles from a HIGH to LOW concentration through protein channels. These protein channels help move specific molecules across the cell membrane - like a babysitter helps a kid complete their project.

Now that you understand Diffusion, you can understand Osmosis. Osmosis is the diffusion of water across a selectively permeable membrane (a membrane that only allows certain things through it). Water flows from a HIGH concentration of water to a LOW concentration of water across the selectively permeable membrane. NO energy is needed for this to occur, so it is called "passive transport".

The third thing we need to cover is Active Transport. This is when cells have to move particles (molecules) against the concentration - so active transport is the moving from a LOW concentration to a HIGH concentration. Because this is going from a LOW to HIGH, energy (ATP) is needed for the particles to move. Since energy is needed, active transport is opposite of passive transport.Most often, active transport happens with the help of a protein pump or proton port.

REVIEW:
1. Diffusion = high to low, no energy needed, passive transport
2. Facilitated Diffusion = high to low, no energy needed, needs help of a protein channel, passive transport
3. Osmosis = diffusion of water, high to low, no energy needed, passive transport
4. Active Transport = low to high and energy is needed

HINTS:
Passive = Goes with the flow, diffusion goes with the flow from high to low.
Osmosis is like Osmosis Jones the movie, its H20 and flows from high to low.
Active = Energetic - needs energy to feel alive and to go from a low to high.

Well, I hope this helps guys! Good luck! :)