Three types of passive transport Simple diffusion Facilitated

Three types of passive transport • Simple diffusion • Facilitated diffusion • Osmosis

Simple diffusion • When molecules are able to cross through the phospholipid bilayer • Molecules need to be: – Small – Hydrophobic

Facilitated Diffusion • When molecules are able to go through the membrane with the help of proteins • Two types of proteins – Channel proteins • Transport ions (molecules with a charge) – Carrier proteins • Transport monomers

Osmosis • The movement of WATER from areas of high to low concentration through a semipermeable membrane

What is happening? Osmosis

Defining terms • Solute – The minor component in a solution; dissolved in the solvent • Solvent – The major component in a solution where the solute is dissolved into • Solution – A liquid mixture in which the minor component (solute) is uniformly distributed within the major component (solvent)

Defining terms • Hypotonic – low solute concentration • Hypertonic – high solute concentration • Water moves from a hypotonic solution to a hypertonic solution until both sides have the same concentration. This is called isotonic.

Which solution is hypotonic? Which solution is hypertonic?

What do you think happened to this red blood cell? Water moved out of the cell

What do you think happened to this red blood cell? Water moved inside the cell

How do cells keep their shape? • By maintaining an isotonic medium