Cell Transport Learning Objectives Explain how passive transport
Cell Transport
Learning Objectives § Explain how passive transport works. § Explain how active transport works.
Cell Membrane § Function: regulates what enters and leaves the cell and provides support § Made of: § Lipid bilayer: support § Proteins: Acts as channels and pumps § Carbohydrates: acts like ID cards § Selectively Permeable: Some substances can pass across and others cannot
Cell Membrane Drawing Outside of cell Proteins Carbohydrate chains Cell Membrane Protein channel Lipid Bilayer
Passive Transport: Diffusion Solutes Outside Cell Membrane Inside Cell Higher concentration of solute on one side of the membrane than the other Diffusion causes net movement of solute particles from the side of the membrane with the higher solute concentration to the side with the lower solute concentration. At equilibrium, particles move equally in both directions, so there is no net change.
Passive Transport: Diffusion • Diffusion: the movement of molecules in a solution from an area of high concentration to an area of low concentration • Passive Transport: Does not require energy • Molecules continue until they reach equilibrium (equal concentrations on both sides of the membrane)
Passive Transport: Facilitated Diffusion
Passive Transport: Facilitated Diffusion
Passive Transport: Osmosis aquaporin sugar water cell membrane
Osmosis
Osmosis • Osmosis: “Diffusion” of water through a selectively permeable membrane • Isotonic: same amount of solute on both sides • Hypertonic: the side with more solute • Hypotonic: the side with less solute Higher Concentration of Water molecules Cell membrane Lower Concentration of Water Sugar Molecules
Osmosis in Cells Isotonic Hypertonic Hypotonic
Passive Transport http: //people. eku. edu/ritchisong/301 notes 1. htm#movement
Active Transport Protein pumps Endocytosis Exocytosis
Active Transport • Active Transport: the movement of molecules against the concentration gradient (uphill) • Requires energy ATP • Often compared to a pump
Active Transport
Movement Direction § Endocytosis: (enter) particles are taken into the cell § Exocytosis: (exit) particles are removed from the cell
Endocytosis
Endoplasmic Reticulum
Levels of Organization § Cells – smallest living level of organization § Tissues – a group of similar cells that perform a particular function § Organs – groups of tissues working together to perform a specific function § Organ Systems – a group of organ that work together to perform a specific function
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