Presentation on theme: "Question of the Day 12-7 Homeostasis = ???"— Presentation transcript:
1Question of the Day 12-7 Homeostasis = ??? What kind of solution can cause a cell to burst (explode)? isotonic, hypotonic, or hypertonic?Water crosses through a ________ ____________ __________ during osmosis.
412-8Question of the DayGet out a clean piece of paper you can turn inQuestions:What is osmosis?What is a hypertonic solution? What happens to the cell in this type of solution?What is a hypotonic solution? What happens to the cell in this type of solution?
9Plasmolysis –loss of turgor pressure in plant cell due to loss of waterWhat happens to a plant during plasmolysis?The plant wiltsThe plants plasma membrane and cytoplasm will shrink away from the cell wall9
10REVIEW: What will happen to an Elodea Leaf in a hypertonic solution? Water will leave the cell……which is called playsmolsis, which will cause the plant leaves to wiltCell membraneCell membrane
11Review If we put Elodea leaves in a hypotonic solution, what happens? Water will move into the cell….….which will cause the cell to swell. If it’s an animal cell it will….…burst, UNLESS the cell has aContractile vacuole to pump the water out. toCell membrane pushingagainst the cell wall
12Summary of Hypo/Hypertonic solution changes on a RBC. 12
13Review If the cell shrinks, it is in what type of solution? If the cell is at equilibrium with it’s environment, its in what type of solution?If the cell swells, it’s in what type of solution?Water –90%Salt – 10%Water 95%Salt 5%Water 64%Salt 36%Water 44%Salt 56%Water 50%Salt 50%Water 50%Salt 50%13
15Egg Lab Report Graph Add a column to you data table: Must be colored Starting Mass (grams)Final Mass (g)Change in mass (g)% Change in Mass((Initial Mass – Final Mass) / Initial Mass) x 100Egg in shell============VinegarCorn SyrupDistilledGraphMust be coloredGraph your starting mass and then use your final mass data which is in blueAdd a column to you data table:“Percent Change in Mass”((Initial Mass – Final Mass) / Initial Mass) x 100Calculate all the changes in mass for your egg
16Egg Lab Report Analysis of your Data: What you should turn in: Be sure you are using the terms we’ve discussed in class in your explanation of your results.ExampleWhat you should turn in:Page 1 – DirectionsPage 2 – Written lab reportPage 3 – GraphPage 4 – Your actual lab procedure
18Selective Permeability – plasma membrane to allows some materials to pass while keeping others outWhy is selective permeability important?So the cell can allow important substance in (water, oxygen, glucose) and keep harmful substances out (bacteria).
19Passive Transport This process uses no ATP Passive Transport – movement of particles across membranes by diffusionThis process uses no ATPMolecules moving from hi concentration low concentration
20Facilitated Diffusion – name for passive transport using transport proteinsDoes not use energy!!!Example:Glucose going from high concentration outside cell low concentration inside the cellWhy doesn’t this need energy?Because it’s still along the concentration gradienttransport proteins
24Transport / carrier proteins – proteins that assist facilitated diffusion
25Ion channels are ion specific proteins transport ions from high concentration to lower concentrationIons like Na+, Ca+, etc are not soluble in lipids, so they must travel through proteins channelsIon channels are ion specificSome channels are always open, some have gateGates open from stimuli: stretching of cell membrane electrical or chemical signals
27Active Transport Active Transport – ATP (adenosine tri-phosphate) – transport of materials against a concentration gradient – requires energyATP (adenosine tri-phosphate) –the ENERGY molecule for the cellBreaks down from ATP ADP (Adenosine di-phosphate)Hydrolysis of the phosphate releases energy
28Active Transport Example http://www. youtube. com/watch
29Sodium-potassium Pump – transfer protein example Transfers Na+ out and K+ inCreates electrical gradient which is important for nerve impulses