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Chapter 7-3. The Cell Membrane; Active & Passive Transport. Gatekeeper Semi-permeable Regulates what comes in and out of the cell Main components: proteins and phospholipids. The Cell Membrane. Found only in plant cells and bacteria cells Main function is support. Cell Wall.
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Chapter 7-3 The Cell Membrane; Active & Passive Transport
Gatekeeper • Semi-permeable • Regulates what comes in and out of the cell • Main components: proteins and phospholipids The Cell Membrane
Found only in plant cells and bacteria cells • Main function is support Cell Wall
Mixtures of substances • Ex. Salt + water; sugar + water Solutions
The movement of molecules from an area of high concentration to an area of low concentration • Molecules tend to “spread out” • Requires no energy Diffusion
When molecules are evenly spread throughout a space • Homeostasis Equilibrium Movie starring Christian Bale called “Equilibrium”
The diffusion of water across a membrane • The cell membrane is selectively permeable • Watch the animation Osmosis
Rule for Osmosis If the area outside the cell has more salt – then water will be sucked out of the cell
"ISO" means the same Cells In Different Solutions
Cell may burst, or organelles called “contractile vacuoles” remove excess water Hypo = less
Cell will shrink or die, plants wilt Hyper = more Why is it dangerous to drink sea water? Why does pouring salt on a slug kill it?
Requires no energy • Diffusion & Osmosis • Facilitated Diffusion – carrier proteins “help” molecules across the membrane Passive Transport
Requires the cell to use energy • Proteins or Pumps found in the membrane move materials across ACTIVE TRANSPORT
Taking “in” large molecules by the cell Endocytosis • Phagocytosis = “phood”, taking in food particles • Pinocytosis = liquid substances
Removing large particles (waste) from the cell • Stuff “exits” the cell • Watch video at http://www.esnips.com/doc/2dad912f-9dcc-4936-89d9-1ae32c6125d2/Chapter-6---Endocytosis-and-Exocytosis • Or McGraw Hill Site EXOCYTOSIS