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Interest Grabber Section 7-1 Are All Cells Alike? All living things are made up of cells. Some organisms are composed of only one cell. Other organisms are made up of many cells. 1. What are the advantages of a one-celled organism? 2. What are the advantages of an organism that is made up of many cells? Go to Section: Section Outline Section 7-1 7–1 Life Is Cellular A. The Discovery of the Cell 1. Early Microscopes 2. The Cell Theory B. Exploring the Cell C. Prokaryotes and Eukaryotes 1. Prokaryotes 2. Eukaryotes Go to Section: Cell Theory 1.All living things are composed of cells. 2.Cells are the basic units of structure and function in living things. (Schleiden and Schwann) 3.New cells are produced from existing cells. (Virchow) Go to Section: Prokaryotic and Eukaryotic Cells Section 7-1 Cell membrane Cytoplasm Prokaryotic Cell Cell membrane Cytoplasm Nucleus Eukaryotic Cell Organelles Go to Section: Single circular chromosome Multiple linear chromosomes Small ribosomes Large ribosomes Go to Section: Interest Grabber Section 7-2 Division of Labor A cell is made up of many parts with different functions that work together. Similarly, the parts of a computer work together to carry out different functions. Working with a partner, answer the following questions. 1. What are some of the different parts of a computer? What are the functions of these computer parts? 2. How do the functions of these computer parts correspond to the functions of certain cell parts? Go to Section: Leuwoenhoek – First simple microscope Robt. Hooke- First to coin the word “cell.” Go to Section: Go to Section: Section Outline Section 7-2 7–2 Eukaryotic Cell Structure A. B. C. D. E. F. G. H. I. Go to Section: Comparing the Cell to a Factory Nucleus Ribosomes Endoplasmic Reticulum Golgi Apparatus Lysosomes Vacuoles Mitochondria and Chloroplasts 1. Mitochondria 2. Chloroplasts 3. Organelle DNA Cytoskeleton Cell Structure Active Art Figure 7-12 The Structure of the Cell Membrane Section 7-3 Outside of cell Cell Membrane controls what goes in and out of the cell Proteins Carbohydrate chains Cell membrane Inside of cell (cytoplasm) Go to Section: Protein channel Lipid bilayer Bilayer Phospholipid Nucleus Control center of the cell – stores genetic information on chromosomes Nucleolus Has information to make ribosomes Cell Alive Link Go to Section: Ribosomes synthesize proteins Go to Section: Endoplasmic Reticulum serves as highways to help transport things throughout the cell. The ER is where lipids are made. The Rough ER makes proteins. Proteins and other molecules are exported in transport vesicles. ER important in homeostasis Go to Section: Go to Section: The Golgi apparatus receives transport vesicles from the ER. It modifies, sorts, packages and sends out material to other destinations inside and outside of the cell. Go to Section: 1. Where do protein products begin their pathway through the cell? in the rough ER Go to Section: 2. How does the Golgi apparatus function in this pathway? It receives vesicles from the ER and repackages their contents into other vesicles, lysosomes, or vacuoles. Go to Section: The formation and functions of lysosomes Lysosomes contain enzymes Recycles old parts Go to Section: Lysosomes contain enzymes made by the rough ER and provide a space where the cell can digest macromolecules safely. These enzymes can also be Go to used Section: to breakdown and recycle old organelles. Vacuoles store material such as water, salts proteins, and carbohydrates In plants the pressure withi the large central vacuol helps to provide suppo for the plant cell. Turgor Pressure. Go to Section: Excess water pumped out Animation Go to Section: Figure 7.14 The contractile vacuole of Paramecium: an evolutionary adaptation for osmoregulation Filling vacuole 50 µm Contractile Vacuole Video (a) A contractile vacuole fills with fluid that enters from a system of canals radiating throughout the cytoplasm. 50 µm Contracting vacuole (b) When full, the vacuole and canals contract, expelling fluid from the cell. Mitochondria and chloroplasts are the main energy converters of the cell. Go to Section: Mitochondria are responsible for aerobic respiration and release the energy stored in food in the form of ATP. Go to Section: Chloroplasts uses photosynthesis to convert radiant energy from the sun into chemical energy (sugar) the plant can use Go to Section: The main differences of plant cells: 1. Plants have a single, large central vacuole. 2. They have a cell wall made of cellulose – used for support and rigidity. 3. They have chloroplasts 4. No centrioles. Go to Section: Figure 7-11 Cytoskeleton Section 7-2 The cytoskeleton composed of microtubules and microfilaments Cell membrane Endoplasmic reticulum Used to maintain the cell shape and for movement Microtubule Microfilament Ribosomes Go to Section: Mitochondrion Centrioles help to organize the chromosomes during cell division. Not found in plant cells. Go to Section: Venn Diagrams Section 7-2 Prokaryotes Eukaryotes Cell membrane Contain DNA Animal Cells Centrioles Go to Section: Plant Cells Cell membrane Ribosomes Nucleus Endoplasmic reticulum Golgi apparatus Lysosomes Vacuoles Mitochondria Cytoskeleton Cell Wall Chloroplasts Large Central Vacuole Nucleus Endoplasmic reticulum Golgi apparatus Lysosomes Vacuoles Mitochondria Cytoskeleton Figure 7-5 Plant and Animal Cells Section 7-2 Smooth endoplasmic reticulum Vacuole Ribosome (free) Chloroplast Ribosome (attached) Cell Membrane Nuclear envelope Cell wall Nucleolus Golgi apparatus Nucleus Mitochondrion Rough endoplasmic reticulum Plant Cell Go to Section: Figure 7-5 Plant and Animal Cells Section 7-2 Nucleolus Nucleus Ribosome (attached) Nuclear envelope Mitochondrion Smooth endoplasmic reticulum Rough endoplasmic reticulum Centrioles Golgi apparatus Animal Cell Go to Section: Ribosome (free) Cell Membrane Membrane proteins can function as channels, Hydrophobic tail markers, receptors Phospholipid Bilayer Hydrophobic portion of protein stuck in middle of membrane Phospho- Phospholipid Bilayer The Cytoskeleton made of protein filaments that help the cell to Go to Section: maintain shape and will also help with cell movement. Go to Section: Do Lab simulation • Go to this site: • http://midpac.edu/~biology/Intro%20Biol ogy/PH%20Biology%20Lab%20Simulati ons/cells/intro.html • Do the lab simulation on cell, all four concepts on left blue panel- take self quiz– screen shot the last page and to Moodle. Gosubmit to Section: Interest Grabber Section 7-3 In or Out? How is a window screen similar to a cell membrane? Read on to find out. 1. What are some things that can pass through a window screen? 2. What are some things that cannot pass through a window screen? Why is it important to keep these things from moving through the screen? 3. The cell is surrounded by a cell membrane, which regulates what enters and leaves the cell. Why is it important to regulate what moves into and out of a cell? Go to Section: Section Outline Section 7-3 7–3 Cell Boundaries A. Cell Membrane B. Cell Walls C. Diffusion Through Cell Boundaries 1. Measuring Concentration 2. Diffusion D. Osmosis 1. How Osmosis Works 2. Osmotic Pressure E. Facilitated Diffusion F. Active Transport 1. Molecular Transport 2. Endocytosis and Exocytosis Go to Section: Diffusionthe random movement of molecules from high concentration to low Go to Section: Diffusion animation Diffusion Go to Section: Would a higher temperature cause diffusion to occur faster or slower? Go to Section: Go to Section: Hydrophillic Head Hydrophobic Tail Figure 7-12 The Structure of the Cell Membrane Section 7-3 Outside of cell Cell Membrane controls what goes in and out of the cell Proteins Carbohydrate chains Cell membrane Inside of cell (cytoplasm) Go to Section: Protein channel Lipid bilayer Bilayer Phospholipid Go to Section: Go to Section: Go to Section: Figure 7-15 Osmosis Section 7-3 Higher Osmotic Pressure Osmosis Animation Osmosis Go to Section: Figure 7.13 The water balance of living cells Hypotonic solution (a) Animal cell. An animal cell fares best in an isotonic environment unless it has special adaptations to offset the osmotic uptake or loss of water. H2O Isotonic solution (b) Plant cell. Plant cells are turgid (firm) and generally healthiest in a hypotonic environment, where the uptake of water is eventually balanced by the elastic wall pushing back on the cell. Osmosis Animation H2O H2O Normal Lysed Turgid (normal) Turgid Leaf H2O Shriveled H2O H2O H2O Hypertonic solution Flaccid H2O Plasmolyzed Plasmolysis video A salt solution is added to the elodea cells- label as many cell parts as you can, including empty space NaCl NaCl NaCl NaCl NaCl NaCl NaCl NaCl Why did the cell shrivel up? What organelle disappeared? Plasmolysis video Turgid Leaf animation Empty Space Analyzing Data Go to Section: Go to Section: Facilitated Diffusion Section 7-3 Glucose molecules High Concentration Cell Membrane Low Concentration Go to Section: Protein channel Passive Transport Animation Passive Transport Go to Section: Go to Section: Figure 7-19 Active Transport Section 7-3 Molecule to be carried Energy Active Transport Video Molecule being carried Go to Section: Go to Section: Active transport animation EXTRACELLULAR FLUID – + Figure 7.18 An electrogenic pump – ATP + H+ H+ Proton pump H+ – H+ + H+ – + CYTOPLASM H+ – Go to Section: + Figure 7.19 Cotransport: active transport driven by a concentration gradient – + H+ ATP – H+ + H+ Proton pump H+ – + H+ – + H+ Diffusion of H+ Sucrose-H+ cotransporter H+ – + – Go to Section: + Sucrose Do Lab simulation • Go to this site: • http://midpac.edu/~biology/Intro%20Biol ogy/PH%20Biology%20Lab%20Simulati ons/biomembrane1/intro.html • Do the lab simulation on Membrane Structure and Transport, then take the practice test – print out the test to turn Goin. to Section: Exploring Endocytosis in Animal Cells In phagocytosis, a cell engulfs a particle by wrapping pseudopodia around it and packaging it within a membraneenclosed sac large enough to be classified as a vacuole. The particle is digested after the vacuole fuses with a lysosome containing hydrolytic enzymes. PHAGOCYTOSIS EXTRACELLULAR FLUID 1 µm CYTOPLASM Pseudopodium Pseudopodium of amoeba “Food” or other particle Bacterium Food vacuole Food vacuole An amoeba engulfing a bacterium via phagocytosis (TEM). In pinocytosis, the cell “gulps” droplets of extracellular fluid into tiny vesicles. It is not the fluid itself that is needed by the cell, but the molecules dissolved in the droplet. Because any and all included solutes are taken into the cell, pinocytosis is nonspecific in the substances it transports. PINOCYTOSIS 0.5 µm Plasma membrane Pinocytosis vesicles forming (arrows) in a cell lining a small blood vessel (TEM). Vesicle Video video Go to Section: Interest Grabber Section 7-4 From Simple to More Complex Many multicellular organisms have structures called organs that have a specific function and work with other organs. Working together, these organs carry out the life processes of the entire organism. Go to Section: Interest Grabber continued Section 7-4 1. Some activities cannot be performed by only one person, but need a team of people. What type of activity requires a team of people to work together in order to complete a task? 2. What do you think are some characteristics of a successful team? 3. How is a multicellular organism similar to a successful team? Go to Section: Section Outline Section 7-4 7–4 The Diversity of Cellular Life A. Unicellular Organisms B. Multicellular Organisms 1. Specialized Animal Cells 2. Specialized Plant Cells C. Levels of Organization 1. Tissues 2. Organs 3. Organ Systems Go to Section: Unicellular Organisms To maintain homeostasis, unicellular organisms grow, respond to the environment, transform energy, and reproduce Go to Section: The Universal Tree of Life • The tree of life – Is divided into three great clades called domains: Bacteria, Archaea, and Eukarya • The early history of these domains is not yet clear Billion years ago Bacteria Eukarya Archaea 0 4 Symbiosis of chloroplast ancestor with ancestor of green plants 1 3 Symbiosis of mitochondrial ancestor with ancestor of eukaryotes 2 Possible fusion of bacterium and archaean, yielding ancestor of eukaryotic cells 1 Last common ancestor of all living things 4 2 3 2 3 1 Origin of life 4 Figure 25.18 Go to Section: Eubacterial •Most numerous organisms on earth •Earliest life forms (fossils date 3.5 billion years old) •Microscopic prokaryotes (no nucleus nor membrane-bound organelles) •Have only one circular chromosome •Have small rings of DNA called plasmids •Most are unicellular •Found in most habitats •Main decomposers of dead organisms so recycle nutrients •Some cause disease Go to Section: Domain Archaea Kingdom Archaebacteria • Found in extreme environments (undersea volcanic vents, acidic hot springs, salty water) •Has different RNA polymerase and ribosomes (rRNA) – similar to eukaryotic cells •Gave rise to eukaryotic cells •Used to be lumped with eubacteria to form the Kingdom Monera Go to Section: The protists of Kindom Protista are the simplest eukaryotes, yet they represent the most diverse group. Most are unicellular, some are colonial, and other are simple multicellular organisms closely related to single protist cells. One group of protists, the algae, are autotrophic photosynthesizers, while the rest eat bacterial or other protistan cells, or small organic particles suspended or dissolved in water. As with all eukaryotic cells, protists contain membrane-bound nuclei and endomembrane systems, as well as numerous organelles Go to Section: amoeba Cells of multicellular organisms become specialized and communicate with one another to maintain homeostasis. Go to Section: Levels of Organization Section 7-4 Muscle cell Smooth muscle tissue Stomach Digestive system organ Organ system Go to Section: Life can be organized into a hierarchy of structural levels. At each successive level additional emergent properties appear. Fig. 2.1 Copyright © 2002 Pearson Education, Inc., publishing as Benjamin Cummings Videos Click a hyperlink to choose a video. Diffusion Osmosis Passive Transport Active Transport Endocytosis and Exocytosis Video 1 Diffusion Click the image to play the video segment. Video 2 Osmosis Click the image to play the video segment. Video 3 Passive Transport Click the image to play the video segment. Video 4 Active Transport Click the image to play the video segment. Video 5 Endocytosis and Exocytosis Click the image to play the video segment. Go Online The latest discoveries in cell study Cell structure activity Career links on histotechnologists Interactive test Articles on cells For links on cell theory, go to www.SciLinks.org and enter the Web Code as follows: cbn-3071. For links on cell membranes, go to www.SciLinks.org and enter the Web Code as follows: cbn-3073. Interest Grabber Answers 1. What are the advantages of a one-celled organism? A one-celled organism has simpler needs and can respond immediately to its environment because its entire cell is immersed in its environment. 2. What are the advantages of an organism that is made up of many cells? In a multicellular organism, different jobs are divided among different groups of cells that work together. Also, a multicellular organism can continue to survive even if it loses some of its cells. Interest Grabber Answers Working with a partner, answer the following questions. 1. What are some of the different parts of a computer? What are the functions of these computer parts? Answers may include: monitor (interfaces with the computer’s environment), software (instructions for how to carry out different jobs), CPU (directs the computer's activities), recycle bin or trash can (storage area for wastes), and so on. 2. How do the functions of these computer parts correspond to the functions of certain cell parts? Students should try to link the functions they described in question 1 to the functions of the different cell structures. The cell needs a way to interface with its environment (cell membrane), instructions for carrying out different jobs (DNA), and a CPU to direct the cell’s activities (nucleus). Interest Grabber Answers 1. What are some things that can pass through a window screen? Answers may include air, fine dust, and rainwater. 2. What are some things that cannot pass through a window screen? Why is it important to keep these things from moving through the screen? Insects, leaves, and other matter that may fall from trees. The screen keeps out annoying insects and objects that may bring dirt into the home. 3. The cell is surrounded by a cell membrane, which regulates what enters and leaves the cell. Why is it important to regulate what moves into and out of a cell? Materials such as oxygen and food that are needed by the cell have to be able to get inside the cell. At the same time, excess materials have to leave the cell. Interest Grabber Answers 1. Some activities cannot be performed by only one person, but need a team of people. What type of activity requires a team of people to work together in order to complete a task? Answers might include building a human pyramid or constructing an arch out of blocks. 2. What do you think are some characteristics of a successful team? Divide up jobs and cooperate well with one another. 3. How is a multicellular organism similar to a successful team? The functions of the organism are divided up among its parts (organs and organ systems). All the parts cooperate to carry out all the functions of the whole organism. This slide is intentionally blank.