7Define osmosisThe diffusion of water across a selectively permeable membrane. Water moves from an area of high to low concentration
8What does high concentration mean? It means an area with a lot of something.Example:sweet Kool-Aid has a lot of sugar (high concentration) and water has a low concentration of sugar (none)
9What happens if I drop these dry sponges into a sink of water? Water moves from high concentration (bucket) to low (sponge)
10Quick write with a partner: Define osmosis and diffusion in your own word.
11Why are osmosis & diffusion important? All living things have certain requirements they must satisfy in order to remain alive.These include exchanging gases (usually CO2 and O2), taking in water, minerals, and food, and eliminating wastes.
12Why are osmosis & diffusion important? All living things have certain requirements they must satisfy in order to remain alive – maintain homeostasisThese include exchanging gases (usually CO2 and O2), taking in water, minerals, and food, and eliminating wastes.These tasks happen at the cellular level.Molecules move through the cell membrane by diffusion
13HomeostasisYour cells are in a balancing act. Some times it is thirsty and some times it has to go. But homeostasis is when it just is “balanced”.
14Quick Write with a partner: Why are osmosis & diffusion important?
15Selectively permeable membrane A membrane that allows only certain materials to cross itMaterials pass through pores in the membrane