190 likes | 204 Views
Learn about the movement of molecules across cell membranes through diffusion, osmosis, and active transport. Understand the concepts of dynamic equilibrium and the transport of large molecules.
E N D
Section 7.4 - Objectives • Predict the movement of water and other molecules across selectively permeable membranes. (SPI 3210.1.7) • Compare and contrast active and passive transport. (SPI 3210.1.8) • Relate diffusion and “dynamic” equilibrium. • Relate osmosis to solute concentration. • Describe how large molecules move across a membrane.
Section 7.4 Cellular Transport
Diffusion Facilitated Diffusion Osmosis Three Modes of Passive Transport Passive TransportMovement of particles across the cell membrane without using energy
Diffusion The net movement of particles from an area of higher concentration to an area of lower concentration. Initial Conditions Diffusion Low High High Low
Dynamic Equilibrium • Reached when diffusion of material into the cell equals diffusion of material out of the cell • Molecules continue to move, but the overall concentration remains the same.
Osmosis This is a special term used to describe the passive transport of water across a selectively permeable membrane.
Water Balancein Animal Cells This is a special term used to describe the passive transport of water across a selectively permeable membrane.
Blood Cell Plant Cell Isotonic Solution • Water and dissolved substances diffuse into and out of the cell at the same rate.
Plant Cell Blood Cell Hypotonic Solution • Solute concentration is higher inside the cell. • Water diffuses into the cell.
Blood Cell Plant Cell Hypertonic Solution • Solute concentration is higher outside the cell. • Water diffuses out of the cell.
Active Transport Movement of particles across the cell membrane using energy Active Transport Using Carrier Proteins
Transport of Large Molecules Exocytosis Endocytosis.
Endocytosis • Process by which the cell surrounds and takes particles into the cell Exocytosis • Secretion of material out of the plasma membrane
Section 7.4 - Review • Relate diffusion & equilibrium. • Describe passive transport. • How does osmosis relate to solute concentration? • Compare & contrast active and passive transport. • How do large molecules move across a membrane?