cells & cellular processes where life begins…. cells... are the simplest collection of matter...
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Cells & Cellular ProcessesCells & Cellular Processes
Where Life Begins…Where Life Begins…
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 changesAre descendents from earlier cells
AllAll Cells Have…
Plasma MembranePlasma Membrane – semipermeable layer that surrounds & protects every cell.
CytoskeletonCytoskeleton – semifluid substance within the membrane
DNADNA – in the form of chromosomes that contain specific genes coordinating cell functions
Ribosomes Ribosomes – tiny organelles that make proteins using instructions from genes
Types of CellsTypes of Cells1.1. ProkaryotesProkaryotes
– 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
Lactobacilluslibrary.thinkquest.org
E.coli on the small intestine
2. Eukaryotes2. Eukaryotes– Contain a “true” nucleus enclosed by a
membrane– Also contain a variety of other membrane-
bound organelles
www.answers.com/topic/cytoskeletonhttp://nobelprize.org/nobel_prizes/medicine/laureates/1999/illpres/
(nucleus)
OrganellesOrganelles“tiny organs”
1.1. NucleusNucleus– 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, nucleolus, the area where ribosomes are produced
http://www.public.iastate.edu/~ttt356/Nucleus.jpg
www.nsf.gov/news/overviews/biology/interact05.jsp
2. Mitochondria2. 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
3. Ribosomes3. 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://www.nsf.gov/news/overviews/biology/assets/interact05.jpghttp://genome.imim.es/courses/Madrid04/exercises/ensembl/images/ribosome.jpg
4. Rough Endoplasmic Reticulum4. Rough Endoplasmic Reticulum
“Rough” because of the ribosomes attached Continuous with
the nuclear membrane Produces internal
membranes Folds, proof-reads &
transports proteins made by ribosomeswww.biologycorner.com
http://www.biology.arizona.edu/CELL_BIO/tutorials/pev/graphics/smooth_er.gif
http://www.mhhe.com/biosci/genbio/enger/student/olc/art_quizzes/genbiomedia/0064.jpg
5. Smooth ER5. 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.comhttp://www.biology.arizona.edu/CELL_BIO/tutorials/pev/graphics/smooth_er.gif
6. Golgi Apparatus6. Golgi Apparatus “Mailroom” of the cell Sorts, packages & exports proteins in vesicles
http://www.daviddarling.info/images/Golgi_apparatus.jpg
http://ghr.nlm.nih.gov/handbook/illustrations/cellgolgi.jpg
Golgi Implications in Disease
AlzheimersParkinson’sMad Cow Lesch-NyhanALS (Lou Gehrig’s)Pick’s Disease
7. Vacuole7. Vacuole Storage organelle for food, water & wastes Especially large in plant cells for the storage of
water
http://www4.alief.isd.tenet.edu/cahowe/PreAPBio/Projects/Cell_files/slide0013_image053.jpg
http://www.daviddarling.info/images/contractile_vacuole.gif
8. Lysosomes8. 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
Lysosomes in Tay SachsMutated 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
9. Peroxisome9. 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 ____ & _____.
Peroxisomes & Disease
ALD – featured in the movie “Lorenzo’s Oil”Zellweger Syndrome
http://www.neuro.jhmi.edu/BrainWaves/2004_Fall/photos/oil.jpg
A Tour of the Cell
The National Science Foundation Tour of the Cell -
http://www.nsf.gov/news/overviews/biology/interactive.jspAn amazing animation of the Inner Life of
the Cell - http://www.studiodaily.com/main/
searchlist/6850.html
The CytoskeletonThe 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:1. Microtubules
2. Actin microfilaments
3. Intermediate filaments
http://upload.wikimedia.org/wikipedia/commons/0/09/FluorescentCells.jpg
1. Microtubules1. Microtubules Hollow tubes that form the thickest of the fibers
in cytoskeletal frameworkMade in centrosome (MTOC) Shape & supports cellServe as tracks for movement of vesicles &
chromosomesOrganelle & vesicle movement along
microtubules is controlled by motor proteins called dynein & kinesin
Dynamic Instability of Microtubules
http://sparkleberrysprings.com/innerlifeofcell.html
AssemblyAssembly DisassemblyDisassembly
http://www.nsf.gov/news/mmg/media/images/microtubule_traffic_h3.jpg
http://www.hhmi.org/bulletin/may2007/chronicle/popups/molecules_1.html
http://www.dnatube.com/view_video.php?viewkey=a8ae0be8b5306971900a&viewtype=?
Microtubules in the cellMicrotubules 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
Microtubules as Chemo TargetMicrotubules 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
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
2. Actin Microfilaments2. Actin Microfilaments Solid rods that are much smaller than
microtubules Two-stranded helical polymers of actin Found just beneath the plasma membrane
http://www.daviddarling.info/encyclopedia/A/actin.html
http://sparkleberrysprings.com/innerlifeofcell.html
Microtubules & Actin Microfilaments
http://publications.nigms.nih.gov/insidethecell/chapter1.html
3.3. Intermediate FilamentsIntermediate 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
Membranes & Transport
Gateways of
cells & organelles
http://www.biology.iupui.edu/biocourses/N100H/cells.html
Structure
http://www.bioteach.ubc.ca/Bio-industry/Inex/
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%3DN
http://commons.wikimedia.org/wiki/Image:Cell_membrane_detailed_diagram.svg
Passive Transport
Does not require energy [High] [Low]
1. Diffusion
2. Osmosis
3. Facilitated diffusion
1. Diffusion
Occurs across the phospholipids– CO2
– O2
– Urea
Lab Information on Diffusion
Dialysis tubing acts as a semipermeable membrane
Which materials can pass through the pores?
Which cannot permeate the bag?
Animation
2. Osmosis
Diffusion of waterWater moves from
– High [water] low [water]– Hypotonic [solute] hypertonic [solute]
Animation
http://www.ualr.edu/botany/osmosis.jpg
http://commons.wikimedia.org/wiki/Image:Turgor_pressure_on_plant_cells_diagram.svg
http://commons.wikimedia.org/wiki/Image:Osmotic_pressure_on_blood_cells_diagram.svg
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
Active Transport
Requires ATP energy– ATP pumps– Cotransport– Endocytosis– Exocytosis
Often goes against concentration gradient
ATP Pumps
Na+/K+ pump
Cotransport
2 molecules transported on the same protein– 1 against the
gradient– 1 with the
gradient
Endocytosis
Engulfing large molecules by wrapping a piece of membrane around it to form a transport vesicle
3 Types of Endocytosis
Phagocytosis– Engulfing solids
Pinocytosis– Engulfing liquids
Receptor-mediated endocytosis– Engulfing with specific receptors
• LDL cholesterol
Exocytosis
Spitting out large molecules
Vesicles fuse with membrane
Endo & Exocytosis
http://en.wikipedia.org/wiki/Phagocytosis
http://www.dnatube.com/view_video.php?viewkey=6ebda4840e7360ce6e7e
Review
http://www.dwm.ks.edu.tw/bio/activelearner/05/ch5intro.html
Tutorial
http://www.dnatube.com/view_video.php?viewkey=4fdd9ee93bdf998c6ca0
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