BIOL110s05-10 - BIOL 110: Principles of Biology Spring 2005...

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Unformatted text preview: BIOL 110: Principles of Biology Spring 2005 Lecture 10, W 2/9/05 http://www.smccd.net/accounts/staplesn/biol110/ • Job for Science/Health majors: Earn some $ on campus as a Lab Prep Assistant in Biology (prefer 1yr + commitment): – See Kim Autrey in 18-209, 306-3296. 18306- • Midterm #1: Friday, 2/11. (Ch. 1-3) – Study/Review Sheets are available • (“Additional Materials”). Materials” – Extra Office Hours: TODAY, 12-3:30pm • Review session TODAY in 16-212. 16– 12:15-2:00 pm.… 12:15pm.… • Bring Questions!!! REVIEW: • Ch. 3: How Cells Are Put Together – Cell Structure – – – – Cell Theory Cell Membranes Prok. vs. Euk Cells Prok. Euk. Organelles (membrane-bound) Euk. (membrane• Nucleus, ER, Golgi, vesicles Golgi, TODAY: • Ch. 3: How Cells Are Put Together – Cell Structure – Euk. Organelles (membrane-bound) Euk. (membrane• • • Mitochondria, Chloroplasts Cytoskeleton Extracellular structures – cell walls, extracellular matrix, junctions 1 B. Mitochondria • ATP-producing powerhouses • Membranes form two distinct two compartments (by 2 membranes!!) • ATP-making machinery embedded in inner mitochondrial membrane – The Powerplant of the cell !!! !!! C. Chloroplasts • Convert sunlight energy to ATP through photosynthesis • Occur in plants and some protistans 2 ** Organelle Origins ** (Endosymbiotic Theory) 1. Mitochondria & Chloroplasts resemble bacteria 1. Have own DNA, ribosomes (Prok. Size!) Prok. 2. Divide on their own 2. May have evolved from ancient bacteria that were engulfed but not digested (Double-membranes!!) engulfed • “Host” prokaryote came to depend upon the ATP and/or Host” photosynthetic sugars made by the smaller microbe • Smaller microbe gained materials and protection D. Cytoskeleton • = PROTEINS! present in all eukaryotic cells – Assembled by MANY polypeptide subunits – = lots of Quaternary (4°) Structure!! • Functions: – Basis for cell shape and internal organization – Allows organelle movement within cells and, in some cases, cell motility 3 1.) Microtubules • Thickest elements • Composed of tubulin tubulin • Arise from microtubule organizing centers (MTOCs = “centrioles” or “Basal Bodies”) • Involved in shape, motility, cell division tubulin subunit 2.) Microfilaments • Thinnest elements • Composed of actin actin • Take part in movement, formation, and maintenance of cell shape actin subunit 4 3.) Intermediate Filaments • Only in animal cells of certain tissues • Most stable cytoskeletal elements – Don’t grow & shorten Don’ much One polypeptide chain • Provide structural structural support (not movement) • Six known groups – Eg: Keratins, nuclear Lamins Eg: Keratins Lamins 4.) Motor Proteins • Interact with microtubles and microfilaments to move parts within cells – Myosin, Dynein (-), Kinesin (+) 5 5.) Flagella and Cilia • Structures for cell motility • 9 + 2 internal structure microtubule Cilia dynein Flagellum Bonus Animation Cilia and flagella Click to view animation. 6 E. Plant Cell Walls Cell Wall • Structural component that wraps around the plasma membrane • Occurs in plants, some fungi, some protistans Secondary cell wall (3 layers) Primary cell wall fibers from flax stem space once occupied by cytoplasm of living cell 2 types of plant cell wall proteins (red) 7 Plant Cuticle • Cell secretions and waxes accumulate at plant cell surface • Semitransparent • Restricts water loss thick cuticle at leaf surface cell of leaf epidermis photosynthetic cell inside leaf Figure 3.20 F. Matrixes between Animal Cells • Animal cells have no cell walls • Some are surrounded by a matrix of cell secretions and other material 8 C. Cell-to-Cell Junctions • Plants – Plasmodesmata plasmodesma • Animals – Tight junctions – Adhering junctions – Gap junctions Primary cell wall of a young plant Plasma membrane 2. Animal Cell Junctions tight junctions gap junction adhering junction (desmosome) intermediate filaments 9 Review for MT1 1. Life - reproduce, DNA, sense/respond (homeostasis), cellular, evolves, uses energy (metabolism) 2. Organization of Life - (Cell Biosphere) Biosphere) 3. Scientific Method: observe, question, predict, test.. 4. Chemistry – atoms, molecules, compounds; Covalent/Ionic/Hydrogen bonds; Octet Rule; Water and pH 5. Biochemicals – CHNOPS elements; Carbo’s, Lipids, Carbo’ Proteins, Nucleic Acids – Structure Function!! Function!! 6. Cells: smallest unit of life; Cell Theory – Prokaryote vs. Eukaryote – Membranes – Fluid Mosaic Model – Organelles: nucleus, endomembrane (ER, golgi, vesicles), golgi, mitochondria, chloroplasts – Endosymbiotic Theory – cytoskeleton, ribosomes, cell wall/matrix, cell junctions ribosomes, light microscopes electron microscopes lipids bacteriophages mitochondria, chloroplasts small molecules most bacteria most animal cells and plant cells proteins 0.1 nm 1 nm 10 nm 100 nm 1 µm 10 µm 100 µm 1 mm Figure 3.4a 10 human eye, no microscope light microscopes hummingbirds humans frog eggs 1 mm 1 cm 0.1 m 1m 10 m 100 m redwoods Figure 3.4a Do not post to Internet Figure 3.4b 1 centimeter (cm) = 1/100 meter, or 0.4 inch 1 micrometer (µm) = 1/1,000,000 meter 1 millimeter (mm) = 1/1,000 meter 1 nanometer (nm) = 1/1,000,000,000 meter 1 meter = 102 cm = 103 mm = 106 µm = 109 nm 11 ...
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This document was uploaded on 03/18/2010.

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