December 6, 2010 Beginning with van Leeuwenhoek Create a time line with the names of those instrumental in discoveries connected with the microscope and the cell theory Describe the cell theory. Notes on 7.1/ 7.2 Problem Solving lab 7.1 NOTEBOOK Check on 6 A B C D 1600 1700 1800 A. Hooke – cork cells B. Leeuwenhock – single lens, saw red blood cells and bacteria C. Schleiden – plants D. Schwann – animal cells Cell Theory 1. All organisms composed of 1 or more cells 2. The cell is the basic unit of organization of organisms 3. All cells come from preexisting cells (cell divides to form 2 identical cells) Chapter 7 Cells Muscle Cell December 7, 2010 Bola Spider No Web Catches with a spider silk thread with a sticky glob on the end (bola) Generates the same scent as the female moth to attract the male moth 600% elastic Sticky irreproducible adhesive Catches up to 8 moths/nite 7.1 The Discovery of Cells History of Cell Theory Cells basic units of living organisms Compound Light Microscope Series of Lenses Adjustable Up to 1500x magnification van Leeuwenhoek – 1 lens Object set on top of screw and adjusted to bring into view Made most discoveries Robert Hooke – 1635-1703 Discovered and named the first Cell Found in Cork Named for monastery cells Theodor Schwann – 1810-1882 German Discovered animals made of cells Father of cytology Discovered Schwann Cells Developed the Cell Theory Matthias Jakob Schleiden 1804-1881 Discovered all Plants made of Cells Together with Schwann developed the Cell Theory Cell Theory 1. All organisms composed of 1 or more cells 2. The cell is the basic unit of organization of organisms 3. All cells come from preexisting cells (cell divides to form 2 identical cells) Different Parts of the Microscope Revolving nosepiece Eyepiece Clip Body tube Coarse adjustment Fine adjustment Condenser Arm Iris diaphragm Stage Objective Mirror Condenser control knob Base http://sps.k12.ar.us/massengale/biology Electron Microscopes 1940’s – uses a beam of electrons instead of natural light to magnify structures up to 500,000x Scanning Electron Microscopes (SEM) scans surface of cells to learn 3D shape Transmission Electron Microscope (TEM) study the structures contained in the cell Scanning Tunneling Microscope (STM) – uses flow of electrons to investigate atoms on the surface of the molecule Electron Micro scope 2 Basic Cell Types 1. Prokaryotes – Cells that do not have an internal membrane bound structure – unicellular like bacteria 2. Eukaryotes – cells containing membrane bound structures multicellular like algae, yeast Organelles – small membrane bound structures allows various chemical reactions to occur simultaneously Brown, Virchov – decided main structure that was responsible for cell division Nucleus – central membrane bound organelle that manages cellular functions Prokaryotes Nucleoid region contains the DNA •Cell membrane & cell wall • Contain ribosomes (no membrane) to make proteins in their cytoplasm http://sps.k12.ar.us/massengale/biology Eukaryotic Cell Contain 3 basic cell structures: Nucleus Cell Membrane Cytoplasm with organelles http://sps.k12.ar.us/massengale/biology Two Main Types of Eukaryotic Cells December 7, 2010 Draw and Label a Prokaryote & Eukaryote Cell ?? What is the function of the plasma membrane? Notes 7.2 PS Lab 7.2 December 13, 2010 Cell Function Worksheet – Due Wed ?? For Plant and Animal Cell Lab Animal Cells – muscles, bone, cerebellum 1. Are these cells alive (once living)? 2. Describe the shape of each cell. 3. Is there a cell wall? Elodea Cell – plant 1. Is the Elodea Cell alive (once living)? 2. Describe the color and shape of chloroplasts 3. Is a cell wall present? 7.2 Plasma Membrane boundary between the cell and its environment Homeostasis – process of maintaining the cells environment Selective Permeability – Process by which the plasma membrane allows some molecules in to the cell while keeping others out (selective – H2O, Calcium, sodium, glucose) Structure of Plasma Membrane Phospholipids – lipids with a phosphate group attached to them Plasma membrane has a glycerol backbone, 2 fatty acid chains and a phosphate group Fluid Mosaic model Model of the plasma membrane where molecules are free to move sideways within a lipid bilayer Polar head outside attracts water but is selectively permeable Other Components Cholesterol – helps stabilize the phospholipids, keeps them from sticking together Transport Proteins – proteins that along the plasma membrane creating a selectively permeable membrane that regulates which molecules enter and leave a cell Fluid Mosaic Model December 14, 2010 ?? Of the day: Describe the Fluid Mosaic Model of Cell or Plasma Membrane – make sure to draw a picture Diffusion Pre-Lab with Notes I will collect grade for Microscope Lab Progress Reports – please have signed and return for 10 pts Cell Membrane Diffusion Lab Every cell is covered by a membrane that controls what can enter and leave the cell. The cell membrane or plasma membrane is selectively permeable. It allows some substances to enter and keeps some substances out. This is important for all life processes. A diagram of cell membrane structure is below. Diffusion Lab (cont) The cell membrane is made up of lipids and proteins. Small non-polar molecules can go right through the membrane by osmosis but ions or larger molecules need assistance by either diffusion and/or by transport proteins. 7.3 Eukaryotic Cell Structure Contains Organelles: Very small size Can only be observed under a microscope Have specific functions Found throughout cytoplasm Plasma Membrane Surrounding the Cell Cell membrane Lies immediately against the cell wall in plant cells Made of protein and phospholipids Selectively permeable http://sps.k12.ar.us/massengale/biology Cell or Plasma Membrane Cell membrane Living layer Controls the movement of materials into and out of the cell Selectively permeable http://sps.k12.ar.us/massengale/biology Plant Cell - Cell Wall Dead layer Large empty spaces present between cellulose fibers Freely permeable Made of cellulose which forms very thin fibers Strong and rigid Found in plant cells http://sps.k12.ar.us/massengale/biology Plant Cell Cell wall Protect and support the enclosed substances (protoplasm) Resist entry of excess water into the cell Give shape to the cell http://sps.k12.ar.us/massengale/biology Control Organelle-Nucleus Nucleus Controls the normal activities of the cell Bounded by a nuclear membrane Contains chromosomes http://sps.k12.ar.us/massengale/biology More on the Nucleus Nucleus Each cell has fixed number of chromosomes that carry genes Genes control cell characteristics http://sps.k12.ar.us/massengale/biology Nucleolus Cell may have 1 to 3 nucleoli Inside nucleus Disappears when cell divides Makes ribosomes that make proteins http://sps.k12.ar.us/massengale/biology Cytoplasm of a Cell Cytoplasm Jelly-like substance enclosed by cell membrane Provides a medium for chemical reactions to take place Contains organelles to carry out specific jobs http://sps.k12.ar.us/massengale/biology Smooth & Rough Endoplasmic Reticulum –assembly and transport of proteins Smooth ER lacks ribosomes & makes proteins USED In the cell Rough ER has ribosomes on its surface & makes proteins to EXPORT http://sps.k12.ar.us/massengale/biology Golgi Apparatus Stacks of flattened sacs Have a shipping side & a receiving side Receive & modify proteins made by ER Transport vesicles with modified proteins pinch off the ends Transport vesicle http://sps.k12.ar.us/massengale/biology Lysosome Contain digestive enzymes Break down food and worn out cell parts for cells Programmed for cell death (lyse & release enzymes to break down & recycle cell parts) http://sps.k12.ar.us/massengale/biology Cell Organelles Vacuole Plants have a large central vacuole Animals several small vacuoles Storage Contains cell sap Sugars, proteins, minerals, wastes, & pigments http://sps.k12.ar.us/massengale/biology Plant Cell Organelles Chloroplast Contain the green pigment chlorophyll Traps sunlight to make sugars (food) Process called photosynthesis http://sps.k12.ar.us/massengale/biology Cell Powerhouse Mitochondrion ( mitochondria ) Rod shape Site of Cellular respiration http://sps.k12.ar.us/massengale/biology In Animal Cells: Mitochondria Active cells like muscles have more mitochondria Burn sugars to produce energy ATP http://sps.k12.ar.us/massengale/biology Different kinds of plant cells Onion Epidermal Cells Guard Cells root hair Root Hair Cell http://sps.k12.ar.us/massengale/biology vacuole cytoplasm nucleus mitochondrion glycogen granule cell membrane http://sps.k12.ar.us/massengale/biology Animal cell No cell wall or chloroplast Stores glycogen in the cytoplasm for food energy Different kinds of animal cells white blood cell Amoeba red blood cell muscle cell cheek cells http://sps.k12.ar.us/massengale/biology sperm nerve cell Paramecium Similarities between plant cells and animal cells Both have a cell membrane surrounding the cytoplasm Both have a nucleus Both contain mitochondria http://sps.k12.ar.us/massengale/biology Differences between plant cells and animal cells Animal cells Plant cells Relatively smaller in size Relatively larger in size Irregular shape Regular shape No cell wall Cell wall present http://sps.k12.ar.us/massengale/biology Differences between Plant Cells and Animal Cells Animal cells Plant cells Vacuole small or absent Large central vacuole Glycogen as food storage Starch as food storage Nucleus at the center Nucleus near cell wall http://sps.k12.ar.us/massengale/biology Structure and Support Cytoskeleton – Support structure, Rods and filaments Constantly changing Microtubules – Thin hollow cylinders Made of proteins Microfilaments Thin, solid protein fibers Movement of the Cell Flagella – long projections that propel the cell with whip like motions Cilia – hair like projections that wave http://www.surrey.ac.uk Cell Analogy Model – 100 pts Title/Communication:/10pts Creativity/Originality/Neatness/10 pts Use of Color and in 3D/10 pts Communication of ideas with Appropriate Analogies / 5 pts ea Total of 12/60 pts Total/100 pts