Cells & Cellular Processes

1. Cells & Cellular Processes Where Life Begins…

2. Cells... • Are the simplest collection of matter that can live • Are the basic unit of structure & function for all living things • Communicate with one another • Sense & respond to environmental changes • Are descendents from earlier cells

3. All Cells Have… • Plasma Membrane – semipermeable layer that surrounds & protects every cell. • Cytoskeleton – semifluid substance within the membrane • DNA – in the form of chromosomes that contain specific genes coordinating cell functions • Ribosomes – tiny organelles that make proteins using instructions from genes

4. Types of Cells E.coli on the small intestine • Prokaryotes • Pro – before; karyon – nucleus • No true nucleus • Nucleoid region • Not a true membrane-bound nucleus but the area where DNA is concentrated • Bacteria are the only examples E. coli Salmonella Lactobacillus library.thinkquest.org

5. www.answers.com/topic/cytoskeleton 2. Eukaryotes • Contain a “true” nucleus enclosed by a membrane • Also contain a variety of other membrane-bound organelles http://nobelprize.org/nobel_prizes/medicine/laureates/1999/illpres/

6. Pro - NO Eu - DO (nucleus)

7. www.nsf.gov/news/overviews/biology/interact05.jsp Organelles“tiny organs” • Nucleus • Control center that directs cellular activity • Contains most of the genes in eukaryotic cells • Enclosed by a nuclear membrane, or envelope, that contains pores • Contains DNA usually in the form of chromatin • Contains the nucleolus, thearea where ribosomes are produced http://www.public.iastate.edu/~ttt356/Nucleus.jpg

8. 2. Mitochondria • Powerhouse of the cell • Produces the bulk of the ATP in the cell during aerobic respiration • Contains its own DNA • Thought be free-living bacteria at one time http://kentsimmons.uwinnipeg.ca/cm1504/Image110.gif

9. 3. Ribosomes • The tiniest organelles; produce in nucleolus • Assemble proteins through the process of translation • Some are “free” in cytoplasm; others are attached to Rough ER http://genome.imim.es/courses/Madrid04/exercises/ensembl/images/ribosome.jpg http://www.nsf.gov/news/overviews/biology/assets/interact05.jpg

10. 4. Rough Endoplasmic Reticulum • “Rough” because of the ribosomes attached • Continuous with the nuclear membrane • Produces internal membranes • Folds, proof-reads & transports proteins made by ribosomes www.biologycorner.com http://www.biology.arizona.edu/CELL_BIO/tutorials/pev/graphics/smooth_er.gif

11. http://www.mhhe.com/biosci/genbio/enger/student/olc/art_quizzes/genbiomedia/0064.jpghttp://www.mhhe.com/biosci/genbio/enger/student/olc/art_quizzes/genbiomedia/0064.jpg

12. 5. Smooth ER • Extension of RER without the ribosomes • Makes lipids for the cell – fatty acids, steroids & phospholipids • Also functions in detoxification of poisons & toxins within the cell www.biologycorner.com http://www.biology.arizona.edu/CELL_BIO/tutorials/pev/graphics/smooth_er.gif

13. http://ghr.nlm.nih.gov/handbook/illustrations/cellgolgi.jpg 6. Golgi Apparatus • “Mailroom” of the cell • Sorts, packages & exports proteins in vesicles http://www.daviddarling.info/images/Golgi_apparatus.jpg

14. Golgi Implications in Disease • Alzheimers • Parkinson’s • Mad Cow • Lesch-Nyhan • ALS (Lou Gehrig’s) • Pick’s Disease

15. 7. Vacuole • Storage organelle for food, water & wastes • Especially large in plant cells for the storage of water http://www.daviddarling.info/images/contractile_vacuole.gif http://www4.alief.isd.tenet.edu/cahowe/PreAPBio/Projects/Cell_files/slide0013_image053.jpg

16. 8. Lysosomes • Enzyme-containing organelles that digest (hydrolyze) cellular waste products, nonfunctional proteins & return usable components to cytoplasm • Enzymes are made in SER http://www.molecularexpressions.com/cells/lysosomes/images/lysosomesfigure1.jpg

17. Lysosomes in Tay Sachs • Mutated genes produce enzymes that are less effective than normal at breaking down fatty cell products known as gangliosides. • Gangliosides build up in the lysosomes and overload cells. http://www.sfn.org/index.cfm?pagename=brainBriefings_TreatingTaySachs http://www.kellogg.umich.edu/theeyeshaveit/congenital/images/tay-sachs.jpg

18. 9. Peroxisome • Enzyme-containing organelles that transfer H+ from various compounds to oxygen • Some break down fatty acids; others break down poisons such as alcohol • H2O2 is often a waste product of peroxisome reactions, and it is a toxin as well – Our body breaks down H2O2 with an enzyme called _______. The products are ____ & _____.

19. Peroxisomes & Disease • ALD – featured in the movie “Lorenzo’s Oil” • Zellweger Syndrome http://www.neuro.jhmi.edu/BrainWaves/2004_Fall/photos/oil.jpg

20. A Tour of the Cell • The National Science Foundation Tour of the Cell - http://www.nsf.gov/news/overviews/biology/interactive.jsp • An amazing animation of the Inner Life of the Cell - http://www.studiodaily.com/main/searchlist/6850.html

21. The Cytoskeleton • Semifluid medium that supports organelles • Consists of a network of fibers that support the cell and allow for organized movement of material. • Fibers include: • Microtubules • Actin microfilaments • Intermediate filaments http://upload.wikimedia.org/wikipedia/commons/0/09/FluorescentCells.jpg

22. 1. Microtubules • Hollow tubes that form the thickest of the fibers in cytoskeletal framework • Made in centrosome (MTOC) • Shape & supports cell • Serve as tracks for movement of vesicles & chromosomes • Organelle & vesicle movement along microtubules is controlled by motor proteins called dynein & kinesin

23. Dynamic Instability of Microtubules Disassembly Assembly http://sparkleberrysprings.com/innerlifeofcell.html

24. http://www.nsf.gov/news/mmg/media/images/microtubule_traffic_h3.jpghttp://www.nsf.gov/news/mmg/media/images/microtubule_traffic_h3.jpg http://www.dnatube.com/view_video.php?viewkey=a8ae0be8b5306971900a&viewtype=? http://www.hhmi.org/bulletin/may2007/chronicle/popups/molecules_1.html

25. Microtubules in the cell • Centrioles • Found in animal cells only • Organize microtubules during cell division • Have a 9 + 3 arrangement • 9 sets of 3 microtubules http://micro.magnet.fsu.edu/cells/centrioles/centrioles.html

26. Microtubules as Chemo Target • Taxol, a chemo drug, works by stabilizing microtubules (green) used in cell division • It halts cells in the process of division http://cose-stor.sfsu.edu/~huiyang/images/cell-fireworks.jpg

27. Cilia & Flagella • Core of microtubules covered by an extension of the cell membrane • 9 + 2 pattern • Anchored by a basal body that has the same 9 + 3 microtubule arrangement as centrioles • Dynein arms are the “motors” responsible for the bending movements of cilia & flagella http://micro.magnet.fsu.edu/cells/centrioles/centrioles.html

28. 2. Actin Microfilaments • Solid rods that are much smaller than microtubules • Two-stranded helical polymers of actin • Found just beneath the plasma membrane http://sparkleberrysprings.com/innerlifeofcell.html http://www.daviddarling.info/encyclopedia/A/actin.html

29. Microtubules & Actin Microfilaments http://publications.nigms.nih.gov/insidethecell/chapter1.html

30. Intermediate Filaments • Mid sized filaments that provide framework for organelle position • The most stable & durable fibers in the Cytoskeleton • Main component in tough coverings (skin, hair, nails) http://campus.queens.edu/faculty/jannr/cells/cell%20pics/cytoskeleton.jpg http://www.studiodaily.com/main/searchlist/6850.html

31. Membranes & Transport Gateways of cells & organelles

32. Structure http://www.bioteach.ubc.ca/Bio-industry/Inex/ http://www.biology.iupui.edu/biocourses/N100H/cells.html

33. http://images.google.com/imgres?imgurl=http://www.iupac.org/didac/Slide%2520Images/Didac%252005/Thumbs/D5%2520CG06.jpg&imgrefurl=http://www.iupac.org/didac/Didac%2520Eng/Didac05/Content/CG06.htm&h=254&w=378&sz=61&hl=en&start=24&tbnid=ukwDqpIAGNcyMM:&tbnh=82&tbnw=122&prev=/images%3Fq%3Dphospholipid%2Bbilayer%26start%3D20%26gbv%3D2%26ndsp%3D20%26svnum%3D10%26hl%3Den%26sa%3DNhttp://images.google.com/imgres?imgurl=http://www.iupac.org/didac/Slide%2520Images/Didac%252005/Thumbs/D5%2520CG06.jpg&imgrefurl=http://www.iupac.org/didac/Didac%2520Eng/Didac05/Content/CG06.htm&h=254&w=378&sz=61&hl=en&start=24&tbnid=ukwDqpIAGNcyMM:&tbnh=82&tbnw=122&prev=/images%3Fq%3Dphospholipid%2Bbilayer%26start%3D20%26gbv%3D2%26ndsp%3D20%26svnum%3D10%26hl%3Den%26sa%3DN

34. http://commons.wikimedia.org/wiki/Image:Cell_membrane_detailed_diagram.svghttp://commons.wikimedia.org/wiki/Image:Cell_membrane_detailed_diagram.svg

35. Passive Transport • Does not require energy • [High]  [Low] • Diffusion • Osmosis • Facilitated diffusion

36. 1. Diffusion • Occurs across the phospholipids • CO2 • O2 • Urea

37. Lab Information on Diffusion • Dialysis tubing acts as a semipermeable membrane • Which materials can pass through the pores? • Which cannot permeate the bag? Animation

38. http://www.ualr.edu/botany/osmosis.jpg 2. Osmosis • Diffusion of water • Water moves from • High [water]  low [water] • Hypotonic [solute]  hypertonic [solute] Animation

39. http://commons.wikimedia.org/wiki/Image:Osmotic_pressure_on_blood_cells_diagram.svghttp://commons.wikimedia.org/wiki/Image:Osmotic_pressure_on_blood_cells_diagram.svg http://commons.wikimedia.org/wiki/Image:Turgor_pressure_on_plant_cells_diagram.svg

40. 3. Facilitated Diffusion • Molecules moving from [high]  [low] but are too big to move between phospholipids • Requires a membrane carrier (facilitator) • Glucose uses this http://www.biology.arizona.edu/chh/problem_sets/kidneysmetals/07t.html

41. Active Transport • Requires ATP energy • ATP pumps • Cotransport • Endocytosis • Exocytosis • Often goes against concentration gradient

42. ATP Pumps • Na+/K+ pump

43. Cotransport • 2 molecules transported on the same protein • 1 against the gradient • 1 with the gradient

44. Endocytosis • Engulfing large molecules by wrapping a piece of membrane around it to form a transport vesicle

45. 3 Types of Endocytosis • Phagocytosis • Engulfing solids • Pinocytosis • Engulfing liquids • Receptor-mediated endocytosis • Engulfing with specific receptors • LDL cholesterol

46. Exocytosis • Spitting out large molecules • Vesicles fuse with membrane

47. Endo & Exocytosis http://www.dnatube.com/view_video.php?viewkey=6ebda4840e7360ce6e7e http://en.wikipedia.org/wiki/Phagocytosis

48. Review Tutorial http://www.dwm.ks.edu.tw/bio/activelearner/05/ch5intro.html http://www.dnatube.com/view_video.php?viewkey=4fdd9ee93bdf998c6ca0