Unit 1: B01, B02, B5.1 Key Notes All known living organisms are made of cells. Levels of organization exist in multicellular organisms. Tissues are a group of cells that all perform the same function. Intro to Microscopes • Parts of a microscope and safe handling procedures. Cells Lab Wrap Up • What type of cells are these? – Which structures can you identify? Cells Lab Wrap Up • What type of cells are these? – Which structures can you identify? Calculating Magnification • Size in the picture = Actual size (real life) X magnification = X • 2000 mm = 20mm x 100x • This equation can be re-arranged to solve for any of the components. Thinking Question • Are all animal cells the same? • Do all plant cells have the same function? • Write down your thoughts and give an example to illustrate. Specialized Cells • Different types of cells perform different functions. • The structure of the cell is related to its function! Cells Perform Specific Functions • Read pg. 24 • As you read about the six types of specialized cells, write down this information about the red blood cell: – a description of the cell type – The function of the cell – How the cell performs its specific function Diffusion • An example you can SMELL • An example you can SEE • Equilibrium: when the concentration of the solute is the same throughout a system. Concentration Diffusion • The net movement of molecules from a region of their higher concentration to a region of their lower concentration down a concentration gradient, as a result of their random movement. Selectively Permeable Membranes • Partially permeable membranes = semipermeable membranes – Only some molecules can pass through the membrane via diffusion. • Cell membranes are semipermeable Cell Membranes Osmosis • The diffusion of water molecules from a region of their higher concentration (dilute solution) to a region of their lower concentration (concentration solution) through a partially permeable membrane. Osmosis • http://www.hartnell.edu/tutorials/biology/ani mations/osmosis/Osmosis.swf Osmosis Lab • Answer the questions at the end of your chicken egg osmosis lab. • Look at your lab observations and data: – What happens when a cell is exposed to pure water for a long time? • Which way did the water move? • Why? – What happens when a cell is exposed to a concentrated sugar solution? • Which way did the water move? • Why? Osmosis in Blood Cells Actual Red Blood Cell Pictures Regular cell at equilibrium Solution with more pure water (dilute solution) Solution with more concetrated solutes Effect of Osmosis on Cells • *Remember – water is always the particle that moves • What about cells with cell walls? – They won’t burst, but they may injure their cell walls. H2O H2O H2O H2O Osmosis and Plant Cells Practice Question Thinking Question • How do plants use the process of osmosis to obtain the water they need for life? Life processes use diffusion • Check out the picture on pg. 29 that shows all the different ways diffusion is used in living organisms. • Draw a similar diagram in your book – you can use your own examples! The Pathway of Water Across a Root Vascular Bundles • Cross Section of a Root: Cross Section of a Stem Dicot Leaf Section of a Leaf • Read your textbook p. 90 - 91 & take notes on Xylem & Phloem. – What do each of the tubes carry? • Both of these tissues are arranged in vascular bundles found in the roots, stem and veins of a leaf. Water Flow • The pathway taken by water through a plant: • Root hair Root cortex cells xylem mesophyll cells Water Flow • Water is being pulled upwards because it is either used up in photosynthesis or evaporated off the leaves. • This creates a “pull” from above . • A water potential gradient is created in the xylem of the stem. • This draws cohesive (sticking-together) water molecules up the plant. Transpiration • Transpiration: Evaporation of water at the surfaces of mesophyll cells followed by loss of water vapour from plant leaves, through the stomata. • http://www.biologymad.com/resources/trans piration.swf Experiment: To demonstrate transpiration Potometers: Experiment: Measuring the rate of water uptake Transpiration • What sort of factors do you think would affect transpiration? • Translocation • Translocation: The movement of sucrose and amino acids in phloem from regions of production to regions of storage or regions of utilization in respiration or growth.