Eagle Zone  -Turn in your current Event to the pink basket  -Write down your homework in AGENDA: Complete “Cell City” homework in your spiral-under Unit 3 on website  -Get out your notes spiral and be ready to take notes when the bell rings.  Announcements: 1. Project Due Next Wednesday by 4pm 2. Quiz over cell organelles and functions next Wednesday (Tues 8 th ) 3. Quiz over identifying organelles in a cell next Friday(Thurs 8 th )

Cell Membrane Outside of cell Inside of cell (cytoplasm) Cell membrane Proteins Protein channel Lipid bilayer Carbohydrate chains

TAKS  Objective 2 – The student will demonstrate an understanding of living systems and the environment.

TEKS Science Concepts  4 -The student knows that cells are the basic structures of all living things and have specialized parts that perform specific functions, and that viruses are different from cells and have different properties and functions.  (B)investigate and identify cellular processes including homeostasis, permeability, energy production, transportation of molecules, disposal of wastes, function of cellular parts, and synthesis of new molecules

Engage  Can you smell what is inside the balloon?

Eagle Zone  1)Give the function of the following cell organelles AND tell what type of eukaryote they are found in: l Golgi apparatus, ribosomes, mitochondria, chloroplast  2)What three organelles are found in a plant cell that are not in an animal cell?  3)What is the main difference between a virus and a bacteria?  4)Why does a virus need a host cell? –15 minutes

Explore  Veggie Lab-Write the questions l Retrieve a piece of vegetable from the beaker labeled water. Describe the following in your LAB BOOK : What does the vegetable look like? (color, shape, size, feel) Try to bend the vegetable. Describe what happens Which direction do you think the water traveled, inside or outside of the cell membrane of the vegetable? Why? l When you are done with BOTH salt and tap water, answer these questions : Define semi-permeability If water is moving across a membrane, what is the name of that process?

Explain: Cell Diversity  Cells within the same organism show Enormous Diversity in: l Size l Shape l Internal Organization

A. Cell Size  Female Egg - largest cell in the human body; seen without the aid of a microscope  Most cells are visible only with a microscope.  Why do you think most cells are so small?

Cells are small for 2 Reasons Reason 1:  Limited in size by the RATIO between their Outer Surface Area and Their Volume. A small cell has more SURFACE AREA than a large cell for a GIVEN VOLUME OF CYTOPLASM.

Cells are Small Reason 2:  THE CELL'S NUCLEUS (THE BRAIN) CAN ONLY CONTROL A CERTAIN AMOUNT OF LIVING, ACTIVE CYTOPLASM.

B. Cell Shape  Diversity of form reflects a diversity of function.  THE SHAPE OF A CELL DEPENDS ON ITS FUNCTION.

Prokaryotic Cell Cell membrane Cytoplasm Nucleus Organelles Eukaryotic Cell C. Internal Organization

Membrane structure  Semi-Permeable- allows some materials to pass through membrane to cell while others are not capable  Selectively Permeable  Amphipathic~ hydrophobic & hydrophilic regions  Fluid Mosaic Model

Outside of cell Inside of cell (cytoplasm) Cell membrane Proteins Protein channel Lipid bilayer Carbohydrate chains The Structure of the Cell Membrane

Explore 2  Cell Membrane Manipulative l In groups, you will construct a model of the cell membrane using the materials provided for you at the table l Once you have constructed your model, have it examined by the teacher for completeness. Each person in your group must say at least 1 thing about the model before your group can be awarded completion points on your lab ticket

Membrane traffic  Passive transport~ diffusion of a substance across a biological membrane (NO ENERGY)  Diffusion~ particles movement from high concentration to low concentration l Osmosis~ the diffusion of water across a selectively permeable membrane

Results of Diffusion  Dynamic equilibrium l Once diffusion has evenly distributed the particles; movement of particles continues with no change in concentration  Homeostasis l Preservation of equilibrium

Diffusion depends on Concentration gradient  Concentration gradient: the difference in concentration of a substance across space  Diffusion is said to move down a concentration gradient  Diffusion continues until there is NO concentration gradient  Ex: O 2 diffuses into oxygen depleted blood

Diffusion Small molecules like WATER, OXYGEN, AND CARBON DIOXIDE can move in and out freely. Large molecules like PROTEINS AND CARBOHYDRATES CANNOT Charged IONS CANNOT

Osmosis~ the diffusion of water across a selectively permeable membrane

Small quiz- use white boards  Osmosis is the diffusion of _______ across a cell membrane.  Osmosis and Diffusion are both types of __________ transport.  Passive transport does or does not require energy?  Small molecules can not move across freely. T or F  Large molecules can move freely. T or F

Three Different Types of Solutions  Isotonic Solution  Hypotonic Solution  Hypertonic Solution

Isotonic Solution  The solute outside the cell is equal in concentration to the solute in the cell.  The cell retains its shape.  water moves equally in both directions

Hypotonic Solutions  Solution outside the blood cell contains a lower [] of solute than inside of the cell.  Water will diffuse in. l cell will lyse (burst).  Animal cells - cytolysis.  Plant cells do not burst- turgur pressure— grocers use this idea

Cells in a Hypotonic Solution

Hypertonic Solutions  The solution outside the cell has a higher [] of solute than inside of the cell.  Water will diffuse out of the cell, l causing the cell to shrink l or crenate  Why should you not salt meat before cooking? CRENATIONPLASMOLYSIS

Cells in a Hypertonic Solution

Review: In what type of solution would these cells be found?

Water balance Summary

Plasmolysis Turgidity

Elaborate  Semi-Permeability Lab  Eggactly What I Predicted

Eagle Zone  Your test over Unit 3 will be Monday (B day and 8 th period) and Tuesday (A day)  Get ready for the scavenger hunt!! You need something to write with  Winner will receive prize tomorrow