* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Download Homeostasis and Transport
Survey
Document related concepts
Cell nucleus wikipedia , lookup
Mechanosensitive channels wikipedia , lookup
Theories of general anaesthetic action wikipedia , lookup
Cytoplasmic streaming wikipedia , lookup
Cellular differentiation wikipedia , lookup
Cell encapsulation wikipedia , lookup
Cell culture wikipedia , lookup
Extracellular matrix wikipedia , lookup
Cell growth wikipedia , lookup
Membrane potential wikipedia , lookup
Signal transduction wikipedia , lookup
Organ-on-a-chip wikipedia , lookup
Lipid bilayer wikipedia , lookup
Cytokinesis wikipedia , lookup
Model lipid bilayer wikipedia , lookup
Cell membrane wikipedia , lookup
Transcript
Across Biological Membranes Review for Transport 1. What are the two parts of a solution? 2. In cells, what is normally the solvent? 3. When would water need to move across the cell membrane? 4. When would solutes move across the cell membrane? Diffusion Movement of molecules from an area of high concentration to an area of low concentration. Concentration Gradient • Difference in concentrations across a space CONCENTRATION GRADIENT Diffusion Equilibrium • A balance between environments • No more NET movement of materials Review Questions 1. What is it called when a difference in concentrations exists across a space? 2. What types of particles have the easiest time moving across a lipid bilayer? 3. Name some molecules that may have difficulty entering or leaving a cell. 4. What organelles (aside from the cell membrane) have one or more lipid bilayers? Diffusion Mainly small, nonpolar Particles diffuse through lipid bi-layers to reach equilibrium Conc. Gradient Egg in solutions Fill beaker 2/3 with vinegar Place egg in solution What will happen to the egg? Egg in solutions Fill a NEW beaker 2/3 with Corn syrup Transfer egg from Vinegar solution What will happen to the egg? Osmosis Diffusion of water • When solute cannot cross membranes to • reach equilibrium, the solvent (water) does Water moves from where it is purest (hi conc.) to where it is least pure (lo conc.) H 2O H2O H 2O H 2O H 2O H2O H 2O H 2O H 2O H 2O H 2O H 2O H 2O H 2O H 2O H 2O Osmotic Solution Types Isotonic Solution • Conc of solute is same outside cell as it is inside • No net movement of water Osmotic Solution Types Hypertonic Solution • Conc. of solute is higher outside cell • Net movement of water out of cell • Plasmolysis occurs Osmotic Solution Types Hypotonic Solution • Conc of solute is lower outside cell • Net movement of water into cell • W/ cell wall: turgor pressure • W/out cell wall: cytolysis How do fish in Hyper/Hypo tonic solutions adapt? What if they move from hyper to hypo tonic environments? Osmotic Solution Types Passive Transport NO ENERGY Active Transport YES Energy Facilitated Diffusion Membrane proteins carry materials through the lipid bilayer. • Molecule binds to membrane protein. • The membrane protein changes shape. • The molecule is released on the other side. Ion Channel Proteins Membrane proteins open passage for materials through the lipid bilayer. • Ions crosse membranes through channels Passive Transport Materials move from high low concentration. No energy is required Includes… • Diffusion • Osmosis • Facilitated Diffusion • Channels Active Transport Often low high concentration E is required Pump • Similar to facilitated diffusion except it’s AT ADP + P ATP Active Transport Endocytosis • Cells engulf large materials (nutrients, enemies) with cell membrane. Active Transport Exocytosis • Pre-packaged materials are released from the cell. Review Questions 1. What’s the difference between active and passive transport? 2. In what direction will particles always diffuse? 3. What happens to a wall-less cell in a hypotonic solution? 4. Osmosis is a specialized form of diffusion. Create a Venn diagram comparing osmosis and diffusion.