Selectively Permeable Membrane- [like a strainer] - contains different size openings called pores - only materials smaller than openings pass through

Diffusion- Movement of molecules from an area where there are many to an area where there are few Examples: food coloring in water, spraying air freshener Simple Rule: EquilibriumEquilibrium/Homeostasis- molecules are equally distributed in an area CONTINUES UNTIL …….

OsmosisOsmosis- movement of WATER molecules from an area where there are many to an area where there are few

Which way will molecules move? What process is it? 10% Water 100% Water Time Osmosis High sugar Low Sugar Time Diffusion

Osmosis can effect plant and animal cells differently  Can you think of which cell organelle that a plant has which an animal cell does not, that may have something to do with this? The Cell Wall!! The Cell Wall!!

Plasmolysis- cell membrane shrinking away from cell wall, due to water exiting cell Why? Salt is a substance that will draw water in its direction. This is why you feel thirsty when you eat something salty. Simple Rule: Salt Water Fresh Water Cell Membrane Plant Cells Plant Cells

100% H 2 O 97% H 2 O 90% H 2 O 97% H 2 O Water rushes into cell, keeps cell rigid Water moves out of cell, Cell membrane pulls away from cell wall 10% NaCl PLASMOLYSIS HYPOTONIC CELLHYPERTONIC CELL HYPO = less TONIC = solution HYPER= more TONIC = solution

100% H 2 O 90% H 2 O 95% H 2 O 100% H 2 O - Water rushes into cell - Cell swells and may burst due to lack of cell wall - Water rushes out of cell -Cell shrinks due to lack of cell wall HYPOTONIC CELL HYPERTONIC CELL

97% H 2 O -Cell does not change, water equal inside and out Equilibrium/Homeostasis ISOTONIC CELL ISO = same TONIC = solution

Animal cells and water movement

Active Transport – Endocytosis- process used by cells to transport INTO large materials [proteins] INTO cell Greek terms : ENDO = inside CYTOSIS = relates to cell requires energy

ExocytosisExocytosis- process used by cell to move wastes OUT or other materials OUT of cell Greek terms : EXO = outside CYTOSIS = relates to cell

What do you know?  What are the 2 general types of cell transport and what is the difference between them?  How does a selectively permeable membrane work?  What is diffusion?  What is osmosis and how is it different in plant and animal cells?  What is the difference between hypertonic, hypotonic, and isotonic cells?  What are the 2 types of active transport and how do they work?