Osmosis, diffusion, and active transport

Tom.p.samuel

What are the similarities and differences between osmosis, diffusion, and active transport

Diffusion is where particles move from an area of high concentration to low concentration across a semipermeable membrane like a cell membrane. It's how substances get in and out of cells - if there's a high concentration of something like glucose outside the cell, it moves across the cell membrane to be used inside hte cell

Osmosis isn't the movement of particles, it's the movement of water from a less concentrated solution to a more concentrated solution to dilute the more concentrated one. You might have done a required practical with potato cores in sugar solutions, where water moves out of the potato cells into the really concentrated sugar solutions, and the potato cores get lighter.

Neither of these need energy to happen, they're passive processes.

Active transport goes in the other direction - from an area of low concentration to an area of high concentration, and because this doesn't result in an equilibrium you need energy to carry this out. This might be in root hair cells where they already have some mineral ions, but they need more out the (less concentrated) soil. The cell will perform respiration to get energy, and move the mineral ions into the cell.

Hope this helps!

Reply 2

gwertymerty

Original post by Tom.p.samuel

What are the similarities and differences between osmosis, diffusion, and active transport

osmosis only involves water. its a special type of diffusion that relates to water potential (from high to low).
diffusion and osmosis are both passive processes (no atp required) that move molecules from a high to low concentration, except diffusion can occur with almost any substance (liquid/gas). both processes use passive movement through a partially permeable membrane
active transport actively (requires atp) moves substances from an area of low to high concentration through a partially permeable membrane using intrinsic transport proteins (carrier and channel)

edit: nvm just read labrador's lol