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Exploring Cells with Microscopy Techniques

Learn about light microscopy and electron microscopy, cell fractionation, cell theory, and functions of prokaryotic and eukaryotic cells. Discover the parts of the nucleus, ribosomes, and the endomembrane system. Uncover the secrets of cell structure and function.

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Exploring Cells with Microscopy Techniques

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  1. Cells

  2. Microscopy LIGHT REFRACT • Light Microscopes (Compound Light Microscopes) • Visible _______________ passed through the specimen then through glass lenses. The lenses __________ (bend) light so the image is magnified for vision. • Advantages: __________, _________ organisms, 1000x magnification • Disadvantages: Light microscope cannot resolve detail finer than _____ nm, can’t see small _______________ • Electron Microscopes (Scanning EM- _______________of specimen and Transmission EM- _______________ parts) • Focus a beam of _______________through specimen or onto its surface. • Advantages: Practical resolution limit is about 2nm (100x improvement over LM), can view detail of surface, 1000x more magnification than LMs • Disadvantages: only _______________organisms (vacuum packed), no color COLOR LIVING 200 ORGANELLES SURFACE INTERNAL ELECTRONS DEAD

  3. http://www.mos.org/sln/sem/semphoto.gif http://upload.wikimedia.org/wikipedia/commons/thumb/b/b1/Optical_microscope_nikon_alphaphot_%2B.jpg/220px-Optical_microscope_nikon_alphaphot_%2B.jpg

  4. Cell Fractionation ORGANELLES • Definition: technique used to take cells apart and separate the major _______________ from one another. • Tool: _______________. • Example: Separating cell parts in a tissue ULTRACENTRIFUGE

  5. Discovery of the Cell • The cell was discovered soon after the invention of the microscope in the 17th century. • Robert ___________ used the term “cell” when he examined cork because they looked like ___________ cells. HOOKE PRISON http://www.nndb.com/people/356/000087095/robert-hooke-1.jpg http://biology.clc.uc.edu/fankhauser/Labs/Cell_Biology/Cells_Lab/cork_100x_PA021953c.JPG

  6. Cell Theory LIFE • Cells are the smallest unit of _____. • All living things consist of cell(s) (Unicellular v. multicellular) • All cells come from __________________ cells, by division (mitosis or binary fission). Cannot “make” cells from _______________ chemicals. PRE-EXISTING NON-LIVING

  7. SURVIVE

  8. Unicellular Organisms FUNCTIONS • The single cell must carry out all __________ of life • As a result, cells of unicellular organisms are usually ______ complex that most cells of multicellular organisms. • Examples: amoeba, bacteria, paramecium MORE http://images.tutorvista.com/content/feed/u2077/Multicellular%20Organisms.jpg http://www.enchantedlearning.com/agifs/Amoeba_bw.GIF

  9. Functions of Life NUTRITION METABOLISM • ___________- obtaining food for energy and growth • _______________- chemical reactions such as cell respiration • ___________- an irreversible increase in cell size • _______________- perceiving and responding to changes in environment • ______________- keeping conditions inside the organism within tolerable limits • _______________- producing offspring sexually or asexually GROWTH RESPONSE HOMEOSTASIS REPRODUCTION http://tcdn.teacherspayteachers.com/thumbitem/Characteristics-of-Living-Things-Foldable/original-57634-2.jpg

  10. E. Coli as a Prokaryotic Cell

  11. Liver Cell as a Eukaryotic Cell

  12. Size of Cells 10-3 10-6 10-9 • SI unit for length is the meter (m) • mm (___) um (___) nm (___) • Examples • Surface area to volume ratios in cells • As objects increase in size, its volume grows at a faster rate than its surface area. • Formulas: V= SA= E3 6E2 http://www.xaraxone.com/webxealot/workbook19/cube_04.gif

  13. Surface Area of Cells (cont) MEMBRANE CELL VOLUME • The plasma _______________ controls the amount of oxygen, nutrients, and wastes to enter and exit the cell. If the _______________is too large, not the whole cell may be serviced. • Therefore, most cells are very _______ so there is a sufficient surface area to accommodate ________. • __________ organisms don’t usually have larger cells but rather a larger _______ of cells. SMALL VOLUME LARGER NUMBER http://mrswolfgang.wikispaces.com/file/view/brauerwoodsoncellsize.JPG/58621590/587x442/brauerwoodsoncellsize.JPG

  14. Parts of the nucleus • Nuclear Envelope- • Nuclear lamina- • Nuclear pores- • Chromosomes- • Chromatin- • _______________ (not membrane enclosed) - appears through the EM as a mass of _______ stained granules and fibers adjoining part of the chromatin. Location of rRNA ____________. NUCLEOLUS DENSELY SYNTHESIS

  15. Ribosomes RIBOSOMES • Cells with high rates of protein synthesis have a larger number of ____________ and more nucleoli. Ex. Pancreas cell • _______ ribosomes- are suspended in the cytosol • _________ ribosomes- are attached to the outside of the endoplasmic reticulum or nuclear envelope. FREE BOUND http://iws.collin.edu/biopage/faculty/mcculloch/1406/outlines/chapter%207/rougher2.jpg

  16. Endomembrane System EUKARYOTIC • Endoplasmic reticulum- network of membranes that accounts for more than half the membrane in many _______________ cells. • ER is a network of _____________- tubules and sacs. • ER _______- cisternal space from the cytosol. CISTERNAE LUMEN http://www.science-art.com/gallery/52/52_10202008105023.jpg

  17. RIBOSOMES Rough Endoplasmic Reticulum (surface has ___________) PROTEINS Functions • Make secretory _______________that specialized cells can use and release. • Example: • _________ factory: grows in place by adding membrane proteins and phospholipids to its own membrane. PANCREAS SECRETING INSULIN INTO BLOOD MEMBRANE http://epiehonorsbiology.wikispaces.com/file/view/ROUGH_ER!!!!!!.jpg/276281726/ROUGH_ER!!!!!!.jpg

  18. RIBOSOMES Smooth ER- lacks ________ SYNTHESIS • Functions • ____________ of lipids, metabolism of carbohydrates, and detoxification of drugs and poisons. • ___________ in the smooth ER help in these processes • Also stores calcium ions that can ________ different responses. • Ex: when a muscle cell is _______________by a nerve impulse, calcium ions rush from the ER lumen into the cytosol and trigger muscle _______________. ENZYMES TRIGGER STIMULATED CONTRACTION http://ars.els-cdn.com/content/image/1-s2.0-S0143416002001823-gr2.jpg

  19. RECEIVING Golgi apparatus: Shipping and ___________ center MANUFACTURING PRODUCTS SENT • center of _______________, warehousing, sorting, shipping. • Location where _______________of the ER are modified, stored and ________ to other destinations. • Structure: consists of flattened unconnected _______________that look like a stack of _______________. • Contains two poles: ___ face and ____ face. • Cis face: _______________department that is located near the ER. Vesicles from the ER can fuse with the cis face of the Golgi. • Trans face: _______________ department. Cisternae move from a cis to trans directions and allow vesicles to pinch off to travel to other sites. • Cisternal maturation model: Golgi is a dynamic structure that progress forward from the cis to the trans face of the Golgi, carrying and _______________their protein cargo as they move. CISTERNAE PITA BREAD CIS TRANS RECEIVING SHIPPING MODIFYING

  20. Animation from: http://www.franklincollege.edu/bioweb/A&Pfiles/week04.html See a Golgi movie

  21. http://creationrevolution.com/wp-content/uploads/2010/11/Golgi-Apparatus-and-ER.jpghttp://creationrevolution.com/wp-content/uploads/2010/11/Golgi-Apparatus-and-ER.jpg

  22. Lysosomes: Digestive Compartments HYDROLYTIC ACIDIC • a membranous sac of _______________enzymes that an animal cell uses to digest macromolecules. • Lysosomal enzymes work best in the ______ surroundings of a lysosome and if it bursts, the enzymes are not very active due to the ______ pH of the cytosol. • _______________- process of engulfing smaller organisms or food particles • Food _________ fuses with a lysosome whose enzymes digest food. • _______________- damaged ___________ becomes surrounded by a membrane and lysosome fuses with it, breaking it down to monomers and returning to cytosol for reuse. NEUTRAL PHAGOCYTOSIS VACUOLE AUTOPHAGY ORGANELLE http://images.tutorvista.com/content/feed/u303/lysosomes%20secondary.gif

  23. http://2.bp.blogspot.com/_guSOnFRs_Ks/TJdlF8WZs6I/AAAAAAAAANg/uJiQqzioAEM/s1600/Lysosome-Functions1.jpghttp://2.bp.blogspot.com/_guSOnFRs_Ks/TJdlF8WZs6I/AAAAAAAAANg/uJiQqzioAEM/s1600/Lysosome-Functions1.jpg

  24. Vacuoles HYDROLYSIS LYSOSOMES • Vacuoles carry out ____________and are similar to ____________. • Other functions: • Food Vacuoles- form by _______________ • Contractile vacuoles- pump excess water out of the cell • Ex.: • Plant Cells: • Central vacuole enclosed by a membrane called ___________. • *Central vacuole develops by fusing ________ vacuoles • *Tonoplast is selective in _______________ solutes *cell sap- solution inside vacuole differs than cytosol PHAGOCYTOSIS FRESH WATER ALGAE TONOPLAST SMALLER TRANSPORTING http://middletownhighschool.wikispaces.com/file/view/plantcell450.jpg/98794271/plantcell450.jpg

  25. Vacuoles (cont) PROTEINS • Uses: • Holds reserves of important organic compounds such as _______________. • Plant cell’s main __________ area of inorganic ions such as K+ and Cl- • Can be used as __________ sites for metabolic by-products that would damage if kept in cytosol. • Some contain __________ that color the cell • Can protect plant by releasing _______________ • Major role in _________ as they absorb water to allow cells to grow without increasing ____________. STORAGE DISPOSAL PIGMENTS POISONS GROWTH CYTOPLASM http://24.media.tumblr.com/tumblr_m4lz7amz5V1qj8btco1_500.jpg

  26. Mitochondria METABOLIC ATP OXYGEN EUKARYOTIC • Mitochondrion: sites of cellular respiration, a __________ process that generates ____ by extracting energy from sugars, fats, other fuels with the help of __________. • Found in almost all ____________ cells. • The number of mitochondria is directly related with the cells ___________ activity. More active cells have _______ mitochondria. • Enclosed by two ____________, each a phospholipid bilayer with a unique collection of embedded _________. METABOLIC MORE MEMBRANES PROTEINS http://upload.wikimedia.org/wikipedia/commons/thumb/0/0c/Animal_mitochondrion_diagram_en_(edit).svg/400px-Animal_mitochondrion_diagram_en_(edit).svg.png http://microbewiki.kenyon.edu/images/thumb/2/25/Mitochondria.gif/400px-Mitochondria.gif

  27. Appearace SMOOTH • Outer membrane is __________ • Inner membrane has many folds (__________) • Two Compartments • Intermembrane space- in between inner and outer membrane • Mitochondrial __________contains: • __________- catalyze cellular respiration • Ribosomes- proteins attach to the cristae • mitochondrial _____ • Mitochondria are __________: changeable, moving, and growing. CRISTAE http://preview.turbosquid.com/Preview/2011/06/09__04_44_22/Mitochondria.jpga25b5219-8803-43de-9a20-d001b44f9f9eLarge.jpg MATRIX ENZYMES DNA DYNAMIC

  28. PLASTIDS Chloroplasts (of the organelle family (________) CAPTURE CHLOROPHYLL • Chloroplasts are the organelle in plants that _________ light energy • They contain ______________ (green pigment) which gives plants a green _______. • Contents of a Chloroplast • __________- flattened interconnected sacs (stacked like poker chips) • __________- stack of thylakoids • __________- fluid outside the thylakoids • Contains: • Chloroplasts are dynamic: changeable, moving, and growing. COLOR THYLAKOIDS GRANUM STROMA ENZYMES RIBOSOMES CHLOROPLAST DNA

  29. http://www.ftexploring.com/photopics/thylakoid1-50.gif

  30. Peroxisomes PEROXIDE • Contain enzymes that transfer hydrogen to oxygen to produce hydrogen __________. • Can detoxify alcohol, poison, etc. by transferring hydrogen to oxygen. • Importance of being membrane bound? http://www.facstaff.bucknell.edu/kfield/organelles/organelleimages/peroxisome.gif

  31. Cytoskeletonhttp://www.diffen.com/difference/Cilia_vs_FlagellaCytoskeletonhttp://www.diffen.com/difference/Cilia_vs_Flagella http://static.diffen.com/uploadz/d/d2/Cilia-vs-Flagella.png http://static.diffen.com/uploadz/d/d2/Cilia-vs-Flagella.png

  32. CILIA Many short WHAT’S THE DIFFERENCE? FLAGELLA Animation from: http://web.jjay.cuny.edu/~acarpi/NSC/13-cells.htm • Few • Long

  33. Extracellular Components SHAPE • Cell Wall of Plant Cells • Purpose: to protect the cell, maintain its __________, and prevent excessive water uptake. • __________________: intercellular junction that allows cytosol to pass through and connect the chemical environments of _________________cells. • Water, small solutes (some proteins and RNA) can pass from cell to cell by moving along fibers of _______________to the plasmodesmata. PLASMODESMATA NEIGHBORING CYTOSKELETON What are cell walls of other organisms made of? Bacteria: PEPTIDOGLYCAN Fungi: PEROXIDE

  34. Extracellular Matrix (ECM) of Animal Cells

  35. Chapter 7 Animation from: http://www.sp.uconn.edu/~terry/images/anim/fluidmem.gif Click here to seeFluidityAnimation

  36. Cell membrane picture • http://www.ibguides.com/images/biology/2.4.1.png

  37. DIFFERENT Cell membranes MOVE! MOVING CHANGING Cell membranes contain many __________ molecules which are constantly ________________ and ________________.

  38. PROPERTIES __________of the Plasma membrane NONLIVING • Boundary- Separates the living cell from the __________ environment • Selectively ____________- allows some substances to cross more easily than other substances PERMEABLE http://www.greetin.gs/phoebecell/photogallery/zz4.gif http://www.mansfield.ohio-state.edu/~sabedon/054semip.gif

  39. Fluid Mosaic Model PROTEINS PHOSPHOLIPIDS • Two of the main parts of membranes are lipids and __________ (carbohydrates are also important). • ________________- most abundant lipid in membranes • _____________molecule- it has both a hydrophilic region and hydrophobic region • The cell membrane is a __________ structure (always moving) with a “mosaic” (assortment) of various proteins embedded in or attached to a bilayer of phospholipids AMPHIPATHIC DYNAMIC http://images.tutorvista.com/content/feed/u544/fluid_%20mosaic_model.jpg www.youtube.com/watch?v=ULR79TiUj80

  40. Fluidity of Membranes HYDROPHOBIC • Membranes are held together mainly by ____________interactions which are much weaker than covalent bonds. • Most of the lipids and proteins can move about __________- in the plane of the membrane • Cholesterol within the membrane reduces __________at moderate temperatures by reducing phospholipid movement and can hinder _______________ at lower temperatures therefore it is considered a “cholesterol buffer.” • membrane fluidity • movement LATERALLY FLUIDITY SOLIDIFICATION http://oregonstate.edu/instruct/bb451/summer12/stryer7/CH12/figure_12_33.jpg

  41. Membrane Proteins- 2 Types INTEGRAL • __________ proteins- penetrate the hydrophobic core of the lipid bilayer and many are transmembrane proteins which completely span the membrane. • ____________ region- consist of one or more stretches of nonpolar amino acids • ____________ region- exposed to the aqueous solutions of both sides of the membrane • ____________ proteins- not embedded in the lipid bilayer and instead are _______________ loosely bound to the surface of the membrane HYDROPHOBIC HYDROPHILIC PERIPHERAL APPENDAGES http://oregonstate.edu/instruct/bb451/winter12/stryer6/CH12/figure12-17.jpg

  42. Cell-Cell Recognition DISTINGUISH • A cell’s ability to ____________one type of cell from another • Example: Sorting of cells into tissues and organs in an animal embryo. • Example: Rejection of foreign cells by the ____________ system. • How do cells recognize each other? • Bind to surface molecules (_________________) on the plasma membrane. • ____________- form when carbohydrates bond covalently to lipids. • ________________- form when carbohydrates bond covalently to proteins. IMMUNE CARBOHYDRATES GLYCOLIPIDS GLYCOPROTEINS http://www.quia.com/files/quia/users/lmcgee/membranetransport/cell-cell-recognition.gif

  43. More on Permeability DISSOLVE • Due to the lipid bilayer, nonpolar molecules can ____________in the lipid bilayer and cross with ease • The hydrophobic core of the membrane ____________the direct passage of ions and polar molecules through the membrane • Proteins in the membrane play a key role in ____________of these hydrophilic molecules. IMPEDES TRANSPORT

  44. Other Functions • Hormone binding sites • Immobilized Enzymes • Cell adhesion • Channels for passive transport • Pumps for active transport MORE SOON

  45. Passive Transport DIFFUSION ENERGY DIFFUSION • Passive Transport • Definition: the ____________of a substance across a membrane with no ____________ investment • ____________: the tendency for molecules to spread out evenly into available space ( NO ENERGY REQUIRED. • Rule of diffusion: movement from ____________ concentration to ____________ concentration. • Concentration gradient- gradual difference in the ____________of solutes in a solution causing movement from a higher to lower concentration. • ____________: diffusion of water • Example: p. 132Water moves from the lower solute concentration (more free water) to the higher solute concentration (less free water) until free water concentration is _______. HIGH LOW CONCENTRATION OSMOSIS EQUAL

  46. ISOTONIC HYPOTONIC • Water balance • ____________: the concentration of water in the cell and the environment is the same. No water movement. • ____________: the concentration of water in the cell is greater than that of the environment. Water will move ____________ the cell into the environment. • ____________: the concentration of water in the cell is less than that of the environment. Water will move from the environment ____________ the cell. • Example: p. 133 How does that affect cells with/without cell walls. • osmosis 1 • osmosis 2 OUTSIDE HYPERTONIC INTO

  47. Facilitated Diffusion PASSIVE SPECIFIC • Definition: ____________ transport with the help of transport proteins. • Most transport proteins are ____________ and only transport particular substances • Two types of transport proteins: • ____________ proteins provide corridors that allow molecules to cross the membrane • ion channels function as gated channels which rely on a stimulus that causes them to open or close. • ____________ proteins undergo a change in shape that translocates the solute-binding site across the membrane. The change in shape may be triggered by the binding and release of the transported molecule. CHANNEL CARRIER

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