Cell Membrane: Osmosis SC.912.L.14.2 Relate structure to function for the components of plant and animal cells. Explain the role of cell membranes as a highly selective barrier (passive and active transport) https://www.youtube.com/watch?v=2-icEADP0J4

EQ: How does water move through the cell? C.M. Osmosis Objective: explain how materials pass through a semipermeable membrane EQ: How does water move through the cell?

Structure and Function Phospholipid bilayer Polar head, 2 fatty acid tails Protein, cholesterol, carbohydrate chains Functions: Controls what enters and exits the cell to maintain an internal balance (semipermeable) Provides protection and support for the cell

Active Transport Drives molecules against the concentration gradient from low to high concentration with ENERGY (ATP) Ex- up a slide ATP

Passive Transport Movement of molecules from high to low concentration without energy Movement of molecules high to low Movement of water from high to low

Osmosis Osmosis is the movement of water across a membrane from a region of high water concentration to a region of low water concetration This generally means from a region with very few dissolved materials to a region with lots of dissolved materials (like salt) How is this different from Diffusion? Diffusion = movement of materials across the membrane form high to low concentration osmosis =movement of WATER across the membrane from high to low concentration

REVIEW!!! What are the properties of water? What behaviors of water allow these properties to exist? Why is water a universal solvent?

Osmosis Jones? Super hero and goes on adventures through the cells in the body Why is he blue? WATER!! Osmosis = movement of water

Activate Your Prior Knowledge! What do the following prefixes mean? Hyper: more; above Hypo: less; below Iso: the same; equal

Compared to the conditions in the cell: Osmosis Compared to the conditions in the cell: Hypertonic: has a higher concentration of dissolved substances Hypotonic: has a lower concentration of dissolved substances Isotonic: has the same (equal) concentrations of dissolved substances

Think, Pair, Share We’ve learned that osmosis is water moving across the membrane of a cell. What do you think would happen to the size of the cell if it was exposed to: A hypertonic solution?: The cell will shrink/ shrivel up as water flows out; the cell could die A hypotonic solution?: The cell will swell as water moves in; could eventually rupture (burst) An isotonic solution?: The size of the cell will not change

Label the following on your notes page. Solution Type Cell shape

How do different solutions affect cells? The concentration of dissolved substances in the solution is the same as the concentration of dissolved substances inside the cell. 10% Isotonic 10% No change

How do different solutions affect cells? In a hypertonic solution, water leaves a cell by osmosis, causing the cell to shrink. 20% Hypertonic 10% shrinks

How do different solutions affect cells? In a hypotonic solution, water enters a cell by osmosis, causing the cell to swell. 10% Hypotonic 20% swells

Osmosis

H2O molecules diffusing INTO a cell.

Osmosis Where would the water go? (hint: where is there more FREE water molecules?)

Check for Understanding Based on your understanding of osmosis, which direction will the water molecules move? Identify whether the exterior conditions are hypo/hyper/isotonic: Outside Inside On osmosis practice sheet- label some beakers just with solution (math)

Check for Understanding There were equal concentrations of dissolved substances inside and outside of the cell, so no net movement will occur (water will go in and out equally). The conditions outside the cell were ISOTONIC. Outside Inside

Check for Understanding Based on your understanding of osmosis, which direction will the water molecules move? Identify whether the exterior conditions are hypo/hyper/isotonic: Outside Inside

Check for Understanding There were more dissolved substances outside the cell, so water will move OUT of the cell. The conditions outside the cell were HYPERTONIC. (this means the conditions inside were hypotonic) Outside Inside

Check for Understanding Based on your understanding of osmosis, which direction will the water molecules move? Identify whether the exterior conditions are hypo/hyper/isotonic: Outside Inside

Check for Understanding There were more dissolved substances inside the cell, so water will move INTO of the cell. The conditions outside the cell were HYPOTONIC. (this means the conditions inside were hypertonic) Outside Inside

How Osmosis Works? Your observations should only take up half of the page or less. http://highered.mheducation.com/sites/9834 092339/student_view0/chapter39/how_osmo sis_works.html During the video record the 4 following observations in your notes: The types of molecules that can cross a lipid membrane. The types of molecules that cannot cross a lipid membrane. The reaction of the water molecules when Urea is added to the right side. The water level changes.

Gummy Bears Which gummy was in tap water and which was in salt? Use science terms to explain what happened to each bear: Hypertonic Hypotonic Isotonic Osmosis Passive transport Energy (ATP) Tap water swells- hypotonic solution (water enters the gummy because there is less dissolved material – so more free water molecules- outside of the cell) osmosis is the movement of water from high WATER to LOW water trying to balance the amount of free water. Salt water shrinks- hypertonic solution (water leaves the gummy because there is more dissolved material- so less free water molecules- outside the cell)

Osmosis Practice Answer the analysis questions based on your observations/data of the gummy bears in salt and tap water. Then, complete the activity to label the solutions and cells on the back. C- level 2 voice H- ask three before me A- gummy questions and osmosis practice sheet M- remain seated in your assigned seat, walking around will be a strike P- work with your pod to complete your questions Success!