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Membranes and Transport. Important Terms. Solvent a solution capable of dissolving other substances Solute a minor component dissolved in solvent. The Cell Membrane. The cell membrane is in charge of what gets in to and out of the cell Import nutrients Export molecules and waste
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Important Terms • Solvent • a solution capable of dissolving other substances • Solute • a minor component dissolved in solvent
The Cell Membrane • The cell membrane is in charge of what gets in to and out of the cell • Import nutrients • Export molecules and waste • If good stuff couldn’t get in and bad stuff couldn’t get out, the cell would die
Fluid mosaic model The cell membrane is made up of phospholipidbilayer(‘2 layers’) This barrier allows certain things to pass through it (eg. water, oxygen) but stops others (eg. ions, macromolecules) and is ‘semi-permeable’ hydrophilic hydrophobic = O2 H2O Na+ Na+ extracellular intracellular H2O O2
Fluid mosaic model This semi-liquid ‘sea’ of lipids has proteins floating within it that help move things across the membrane **I will draw the important parts on the board with you...**
Back to membrane transport... • There are 2 types of membrane transport: • Passive transport • Diffusion • Facilitated diffusion • Osmosis • Active transport • Protein pumps • Endo/Exocytosis • Transport happens through phospholipidbilayer or membrane proteins only NO energy needed(it just happens!) Energy needed(otherwise it won’t happen)
Important Terms • Permeable • allowing material through • Impermeable • not allowing material through • Semi-permeable • allowing some material through but not others
Diffusion Movement of molecules from an area of high concentration to an area of low concentration
Osmosis Osmosis is the movement of water molecules through a semi-permeable membrane into a region of higher solute concentration