Lecture4BIO115Winter11d2l

theendosymbiotictheory theendosymbiotictheory

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Unformatted text preview: Contain DNA The Mitochondrion The Mitochondrion • Found in virtually all eukaryotic cells • 1 ­ 10 µ m long, 0.5 ­ 1 µ m diameter • Site of cellular respiration, ATP synthesis • Number in cell correlates with level of metabolic activity • Exhibit remarkable mobility and plasticity The Mitochondrion Food and Oxygen 2 Water, CO , ATP The Chloroplast The Chloroplast • Unique to photosynthetic cells of plants and algae • Site of photosynthesis, process by which light is transformed to chemical energy • Measures 2 µ m by 5 µ m • Mobile and plastic; 3 major compartments The Chloroplast 2 Water, CO , ATP Food and Oxygen Chloroplasts Chloroplasts The Endosymbiotic Theory The Endosymbiotic Theory • Chloroplasts and mitochondria are the descendants of resident aliens!! The Endosymbiotic Theory The Endosymbiotic Theory • Endo: within • Symbiotic: two organisms of different species live in close association • Mitochondria and chloroplasts have characteristics of free­standing cells • Sequencing mtDNA shows all mitochondria are descended from a single species of bacteria The Endosymbiotic Theory The Endosymbiotic Theory • Mitochondria invaded early version of today’s eukaryotic cells, 2 billion yrs ago • Both bacterial and eukaryotic cells benefited • Host provided food to bacteria • Bacteria allowed host to live in oxygenated world The Endosymbiotic Theory The Endosymbiotic Theory Summary for Mitochondria and Summary for Mitochondria and Chloroplasts • Contain DNA that encodes some of their proteins • Sites of energy production within the cell • Mitochondria utilizes oxygen, chloroplasts generate oxygen The Cytoskeleton The Cytoskeleton • • • 1. 2. 3. A network of protein filaments that extends throughout the cytoplasm Dynamic structure providing support and movement Three types: Microfilaments Intermediate filaments Microtubules Cytoskeletal Filaments Cytoskeletal Filaments The Cytoskeleton Microtubule The Cytoskeleton • Roles in: 1.Support 1.Cell motility 1.Internal highway for organelles Support: Nuclear Lamina Support: Nuclear Lamina Cell Motility Cell Cell Motility: Flagella and Cilia Cell Cilia and Flagella Cilia and Flagella • • • • 1. 2. Extensions that project from cells Found in numerous cell types Same internal structure Roles: Move liquid over surface of cell Propel single cell through a fluid Differences Differences • Flagella are longer than cilia • Many cilia, but one flagellum per cell • Cilia make back­and­forth movements • Flagella make undulating whiplike waves Videos of Cilia and Flagella Videos of Cilia and Flagella • http://video.search.yahoo.com/search/vide o;_ylt=Av8yl4sjsHpYq3eEaOiHg.qbvZx4? p=flagella+and+cilia&toggle=1&cop=mss& ei=UTF­8&fr=yfp­t­701 Clinical Significance of Mutant Clinical Significance of Mutant IFs • Epidermolysis bullosa simplex­ mutations in keratins results in fragile skin that causes easy blistering Epidermolysis bullosa Epidermolysis bullosa Epidermolysis bullosa Internal Highway Internal Highway • http://www.dynamicscience.com.au/tester/solutions/biology/cell/cyto skltnrnspt.gif Summary Summary • Chloroplasts and mitochondria: sites of energy conversion • The cytoskeleton is a network of fibers that organizes structures and activities in the cell • Cilia and flagella are motile appendages made primarily of microtubules The Cell as a Factory The Cell as a Factory...
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This note was uploaded on 04/26/2011 for the course BIO 115 taught by Professor Pamment during the Winter '11 term at DePaul.

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