* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Download 08 Cellular Transport Student
Survey
Document related concepts
Cytoplasmic streaming wikipedia , lookup
Tissue engineering wikipedia , lookup
Cell nucleus wikipedia , lookup
Signal transduction wikipedia , lookup
Extracellular matrix wikipedia , lookup
Cell growth wikipedia , lookup
Cell culture wikipedia , lookup
Cell encapsulation wikipedia , lookup
Cellular differentiation wikipedia , lookup
Cytokinesis wikipedia , lookup
Cell membrane wikipedia , lookup
Endomembrane system wikipedia , lookup
Transcript
10/13/15 Bellwork • Add the following prefixes to your sheet: iso— hypo— hyper— endo— Intra— exo— extra— equal low high inside inside outside outside Add these to your pre/suffix sheet cyto – —lysis cells break down Bell work—write your responses on a piece of paper and be ready to discuss Figure A 1. How do the plant cells in figures A and B differ? 2. What is the effect of this difference on the plants? Figure B 3. After eating a sugary or salty snack, why are you so thirsty? The Life of a Cell Cellular Transport and the Cell Cycle Cellular Transport Osmosis: Diffusion of Water • Osmosis: The diffusion of water across a selectively permeable membrane • Regulating the water flow through the plasma membrane is an important factor in maintaining homeostasis within a cell. What controls osmosis? • Unequal distribution of particles, called a concentration gradient, is one factor that controls osmosis. Before Osmosis Selectively permeable membrane After Osmosis Water molecule Sugar molecule Cells in an isotonic solution H2O H2O Water Molecule Dissolved Molecule • Most cells are surrounded by water solutions. http://highered.mheducation.com/sites/00724 95855/student_view0/chapter2/animation__h ow_osmosis_works.html Cells in an isotonic solution • In an isotonic solution, the concentration of dissolved substances in the solution is the same as the concentration of dissolved substances inside the cell. H 2O H2O Water Molecule Dissolved Molecule Cells in an isotonic solution • In an isotonic solution, water molecules move into and out of the cell at the same rate, and cells retain their normal shape. H2O H2O Water Molecule Dissolved Molecule Cells in an isotonic solution • A plant cell has its normal shape and pressure in an isotonic solution. Cells in a hypotonic solution • In a hypotonic solution the concentration of dissolved substances is lower in the solution outside the cell than the concentration in the cell. H2O H2O Water Molecule Dissolved Molecule Cells in a hypotonic solution • Water enters a cell by osmosis, increasing cell pressure (called turgor pressure) and causing the cell to swell. • Plant cells swell beyond their normal size as pressure increases. Cells in a hypertonic solution • In a hypertonic solution the concentration of dissolved substances outside the cell is higher than the concentration inside the cell. H2O H2O Water Molecule Dissolved Molecule Cells in a hypertonic solution • Water leaves a cell by osmosis, causing the cell to shrink. • Plant cells lose pressure as the plasma membrane shrinks away from the cell wall. Bellwork 10/20 Fill in the blanks: You decide to buy a new fish for your freshwater aquarium. When you introduce the fish in its new tank, the fish swells up and dies. You later learn that the fish was from the ocean. Based on what you know of tonicity, the most likely explanation is that unfortunately the fish went from a(n) ____ solution into a(n) _____ solution. Cellular Transport Foldable Hypotonic Solution Isotonic Solution Hypertonic Solution How osmosis affects cells in… Draw a picture of a cell In a hypotonic solution Inside front flap 5 points Under flap Hypotonic Solution— Use your notes to describe the effect hypotonic solutions have on cells Isotonic Solution Hypertonic Solution 5 points How osmosis affects cells in… 30 Points Total Passive Transport • Passive transport: movement of materials through a membrane that does not require the cell to use energy • Facilitated diffusion: the passive transport of materials across the membrane using transport proteins. Passive Transport • Some of the proteins form channels for the molecules to flow through with the concentration gradient. • Carrier proteins change shape to allow a substance to pass through with the concentration gradient. Active Transport • Active transport: movement of materials through a membrane against a concentration gradient that requires energy from the cell Carrier proteins Plasma membrane Concentration gradient Cellular energy Step 1 Step 2 Transport of Large Particles • Endocytosis: a process by which a cell surrounds and takes in material from its environment. Nucleus Wastes Digestion Endocytosis Exocytosis Transport of Large Particles • The material is engulfed and enclosed by a portion of the cell’s plasma membrane. Nucleus Wastes Digestion Endocytosis Exocytosis Transport of Large Particles • The resulting vacuole with its contents moves to the inside of the cell. Nucleus Wastes Digestion Endocytosis Exocytosis Transport of Large Particles • Exocytosis: the expulsion or secretion of materials from a cell. Nucleus Wastes Digestion Endocytosis Exocytosis Transport of Large Particles • Endocytosis and exocytosis both move masses of material and both require energy. Nucleus Wastes Digestion Endocytosis Exocytosis