cells!. prokaryotic vs. eukaryotic (prokaryotes vs. eukaryotes) prokaryotes (bacteria)eukaryotes ★...
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CELLS!PROKARYOTIC vs. EUKARYOTIC
(prokaryotes vs. eukaryotes)Prokaryotes (bacteria) Eukaryotes Simple organism ★ Complex organism Smaller ★ Larger Cytoplasm ★ Cytoplasm Cell Membrane ★ Cell membrane Cell Wall ★ Cell Wall (plants,
fungi Circular DNA (“nucleoid region”) and some protists) Some have flagella or pili ★ Some have flagella
or No membrane-bound organelles cilia Harvest light (photosynthesis,★ Have membrane-bound
decompose/recycle dead organisms, organellessome cause disease, involved inimportant industrial processes
CELLS!PROKARYOTE vs. EUKAROTE
Electron Micrograph
http://www.stolaf.edu/people/giannini/cell/nuc.htm
EUKARYOTES
★ Greek = “true nucleus”
★ Compartmentalized with organelles (membrane-bound structures)
★ Eukaryotic cells include: plant, animal, fungi, protist
PLANT vs. ANIMAL
EUKARYOTIC ORGANELLESPLANT ANIMAL
★ Cell Wall ★ Centriole★ Chloroplast ★ Cilia or Flagella★ Large central vacuole ★ Many small vacuoles★ Cell/Plasma Membrane ★ Cell/Plasma Membrane★ Cytoplasm/Cytosol ★ Cytoplasm/Cytosol★ Mitochondria ★ Mitochondria★ Ribosomes ★ Ribosomes★ Nucleus ★ Nucleus★ Nucleolus ★ Nucleolus★ Nuclear Envelope/Membrane★ Nuclear Envelope/Membrane★ Rough Endoplasmic Reticulum (E.R.) ★ Rough
Endoplasmic Reticulum★ Smooth E.R. ★ Smooth E.R.★ Lysosomes ★ Lysosomes★ Golgi Body/Apparatus ★ Golgi Body/Apparatus★ Cytoskeleton ★ Cytoskeleton
EUKARYOTIC ORGANELLES
Structure Description FunctionNucleus
Nucleolus
Endoplasmic Reticulum
(Smooth & Rough)
Golgi Apparatus
Lysosomes
Mitochondria
Chloroplasts(Plant)
EUKARYOTIC ORGANELLES
Structure Description FunctionCentrioles(Animal)
Cytoskeleton
Flagella/Cilia(Animal, fungi and
some protists)
Central Vacuole (Plant)
Cell Wall(Plant)
Cytoplasm/Cytosol
Ribosomes
EUKARYOTIC ORGANELLES
THE NUCLEUS★ Latin = “kernel” or “nut”
★ First described by Robert Brown (1831)
★ Most eukaryotic cells contain one central nucleus
★Fungi have many nuclei
★ Contains Nucleolus (where synthesis of ribosomal RNA takes place)
★ Nucleus protected by Nuclear Envelope/Membrane (which contains nuclear pores)Structure Description Function
Nucleus Usually spherical surrounded by double membrane that contains chromosomes
Control center of cell; directs protein synthesis and cell reproduction.
Nucleolus Site of genes for ribosomal RNA (rRNA) synthesis
Assembles ribosomes
EUKARYOTIC ORGANELLES
THE NUCLEUS
http://www.cartage.org.lb/en/themes/Sciences/Zoology/AnimalPhysiology/Anatomy/AnimalCellStructure/Nucleus/Nucleus.htm
http://www.frontiers-in-genetics.org/en/pictures/nucleus_1.jpg
EUKARYOTIC ORGANELLES
THE ENDOPLASMIC RETICULUM★ Endoplasmic = “within the cytoplasm”
★ Reticulum = Latin for “a little net”
★ ROUGH E.R.: Contain many ribosomes, which appear pebbly or “rough”, and are destined to be exported from the cell; synthesizes proteins.
★ SMOOTH E.R.: Relatively few or no ribosomes; may contain enzymes which can 1) carry out lipid synthesis (testes, intestine, and brain) or;
2) carry out detoxification of drugs (liver)
Structure Description Function
Endoplasmic Reticulum(Smooth & Rough)
Network of highly folded phospholipid membranes within the cytoplasm
Forms compartments and vesicles; participates in protein and lipid synthesis; transports synthesized proteins
EUKARYOTIC ORGANELLES
THE ENDOPLASMIC RETICULUM
http://academic.brooklyn.cuny.edu/biology/bio4fv/page/rougher.htm
http://www.ccs.k12.in.us/chsBS/kons/kons/eukaryotic%20cell/cytoplasm_and_its_associated_str_files/image002.jpg
EUKARYOTIC ORGANELLES
THE GOLGI BODY/APPARATUS★ Flattened stacks of tubular membranes
★ Smooth, membranous structure located near the middle of the cell
★ Receives proteins and lipids from the E.R.
★ Abundant in glandular cells
★ Modifies and sorts proteins
★ Packages proteins into membrane-bound structures, called vesicles, to be sent to appropriate destinations
★ Similar to a post officeStructure Description Function
Golgi Body/ApparatusFlattened stacks of tubular membranes
Sorts, packages and transports proteins for export from the cell
EUKARYOTIC ORGANELLES
THE GOLGI BODY/APPARATUS
http://www.bu.edu/histology/i/20303ooa.jpg
http://media-2.web.britannica.com/eb-media/52/116252-004-9615DB80.jpg
EUKARYOTIC ORGANELLES
THE LYSOSOME★ Membrane-bounded digestive vesicles
★ Arise from the Golgi Apparatus
★ Contain degrading enzymes which break down old organelles
★ Enzymes also function to eliminate harmful or foreign cells through phagocytosis
★ Include microbodies (glyoxysome, peroxisome)
Structure Description Function
LysosomeVesicles derived from Golgi apparatus that contain digestive enzymes
Digests worn-out organelles and foreign or harmful cells; acts like a “garbage disposal”; plays a role in cell death (“suicide sacs”)
EUKARYOTIC ORGANELLES
THE LYSOSOME
http://www.stolaf.edu/people/giannini/cell/lys/autophag.jpg
http://www.cartage.org.lb/en/themes/sciences/zoology/AnimalPhysiology/Anatomy/AnimalCellStructure/Lysosomes/lysosome.jpg
EUKARYOTIC ORGANELLES
THE MITOCHONDRION★ Plural = Mitochondria
★ Peanut-shaped with outer membrane and highly folded inner membrane (cristae)
★ Have their own DNA (mitochondrial DNA or mDNA) important for oxidative metabolism
★ Transform energy for the cell; “powerhouse” of the cell
★ Similar to a battery, generator or power plant
★ Cells have many mitochondria (ex: liver cells have up to 2000!)
★ Each time the cell divides, a mitochondrion divides in two
Structure Description Function
MitochondriaPeanut shaped structure with double membrane (outer membrane and highly folded inner membrane called cristae)
“Powerhouse” of the cell; sites of oxidative metabolism
EUKARYOTIC ORGANELLES
THE CHLOROPLAST★ Greek: chloro = “green”; plasts = “form “ or “entitiy”
★ Commonly in plant cells
★ Contain pigment called chlorophyll (gives plants their green color)
★ Carry out photosynthesis
★ Typically contain one to several hundred
★ Contain two membranes; closed compartment of stacked membranes called grana which have disk-shaped structures called thylakoids ; surrounding thylakoid is a fluid matrix called stroma
★ Other DNA-containing organelles in plants = plastids (leicoplasts; amyloplasts)Structure Description Function
ChloroplastFlat, disk-shaped green organelle with two membranes; contain chlorophyll, a photosynthetic pigment
Site of photosynthesis; produces food for the cell
EUKARYOTIC ORGANELLES
CHLOROPLAST
http://upload.wikimedia.org/wikipedia/commons/4/49/Plagiomnium_affine_laminazellen.jpeg
http://virtualbiologytutor.co.uk/images/chloroplast.jpg
EUKARYOTIC ORGANELLES
THE CENTRIOLES★ Microtubule Assembly Centers
★ Composed of 9 triplets of microtubules
★ Microtubules = long, hollow cylinders which influence cell shape, move the chromosomes in cell division, and provide structure for flagella and cilia
★ Barrel-shaped organelles found in animals and most protists
★ Plants and fungi lack centrioles
★ Occur in pairs, usually at right angles
Structure Description Function
CentriolesOccur in pairs and made of microtubules; in animal cells and most protists
Important in cell division, cell shape and structure for flagella and cilia
EUKARYOTIC ORGANELLES
CENTRIOLES
http://upload.wikimedia.org/wikipedia/commons/4/49/Plagiomnium_affine_laminazellen.jpeg
http://images.protopage.com/view/721389/3ydo50yjpdnqy8ag4flqbd1un.jpg
EUKARYOTIC ORGANELLES
THE CYTOSKELETON★ Interior framework of the cell
★ Network of protein fibers that support the shape of the cell and anchor organelles to fixed locations
★ Stretches the plasma membrane like the poles on a circus tent!
★ Allows cells to alter rapidly alter shape
Structure Description Function
CytoskeletonNetwork of protein filaments
Provides internal structural support; helps in cell movement
EUKARYOTIC ORGANELLES
CYTOSKELETON
http://www.noble.org/press_release/plantbio/blancaflornasa/cytoskeleton.jpg
http://www.ibri.org/RRs/RR051/51cytoskeleton.gif
http://migration.files.wordpress.com/2007/07/cytoskeleton02.jpg
EUKARYOTIC ORGANELLES
FLAGELLA/CILIA★ Made of microtubules
Aid the cell in locomotion or feeding Motion is similar to that of oars in a rowboat Flagella are longer projections that move with a whip-like
motion Cilia are shorter, numerous projections that look like hairs. Some protists use a pseudopod (“false foot”) to crawl; similar
to squeezing a water balloon at one end forces the balloon to bulge out at the other end.
Structure Description Function
Flagella/CiliaCellular extensions made up of pairs of microtubules
Aid the cell in locomotion (movement) or feeding
EUKARYOTIC ORGANELLES
CILIA FLAGELLA
http://img.sparknotes.com/figures/2/2faaa24e75677b6732cd24bf35c357da/flagella.gif
http://www.ibri.org/RRs/RR051/51cytoskeleton.gif
http://www.bio.miami.edu/~cmallery/150/proceuc/c27x7x3flagella.jpg
http://upload.wikimedia.org/wikipedia/commons/thumb/8/82/Eukaryotic_cilium_diagram_pl.svg/120px-Eukaryotic_cilium_diagram_pl.svg.png
EUKARYOTIC ORGANELLES
CENTRAL VACUOLE★ In Plant cells:
Large sac used to store mainly water and other materials (sugars, ions and pigments)
Helps to increase the surface-to-volume ratio by applying pressure to cell membrane.
In Animal cells: contain many small vacuoles for temporary storage
Structure Description Function
Central VacuoleIn plant cells, large organelle filled with mainly water, and other materials; takes up most of cell
Storage center for water and other materials; helps maintain volume of cell
EUKARYOTIC ORGANELLES
CENTRAL VACUOLE
http://www.ibri.org/RRs/RR051/51cytoskeleton.gif
http://micro.magnet.fsu.edu/cells/plants/images/plantvacuolesfigure1.jpg
http://biology.unm.edu/ccouncil/Biology_124/Images/centralvacoule.bmp
http://images.protopage.com/view/721661/d2fz30gplfcumntwhpv6jr25g.jpg
Animal Cell
Plant Cell
Animal CellFood vacuoles (fv12, fv13, fv14 and contractile vacuole (cv)
http://www5.pbrc.hawaii.edu/allen/ch19/01h-vor710401-28.html
EUKARYOTIC ORGANELLES
CELL WALL★ In Plant and bacterial cells:
Composed of fibers made out of cellulose polysaccharide) Cell walls in plants are thicker and stronger than those in
bacteria (which are primarily made out of protein polysaccharide)
Made up of a primary and secondary wall Also present in fungi and some protists
Structure Description Function
Cell WallIn plant cells, outer layer of cellulose; in bacteria, outer layer of protein; also found in fungi and some protists
Protection and support
EUKARYOTIC ORGANELLES
CELL WALL
http://www.learner.org/courses/essential/life/images/show2.leaf.jpg
http://www.ibri.org/RRs/RR051/51cytoskeleton.gif
http://library.thinkquest.org/C004535/media/cell_wall.gif
EUKARYOTIC ORGANELLES
CYTOPLASM / CYTOSOL Clear, gelatinous fluid that fills the interior of the cell
excluding the nucleus Contains sugars, amino acids and proteins that the cell uses
to carry out its everyday activities
Structure Description Function
Cytoplasm/CytosolClear, gelatinous fluid that fills the inside of the cell
Protection and support
EUKARYOTIC ORGANELLES
CYTOPLASM / CYTOSOL
http://www.cartoonstock.com/lowres/rjo0896l.jpg
http://www.ibri.org/RRs/RR051/51cytoskeleton.gif
http://www2.puc.edu/Faculty/Gilbert_Muth/art0063.jpg
EUKARYOTIC ORGANELLES
RIBOSOMES Sites of protein synthesis (where the cell produces proteins
according to the directions of DNA) Consist of two subunits (small and large) composed of rRNA
and protein The individual subunits are synthesized in the nucleolus and
then move through the nuclear pores to the cytoplasm, where they assemble.
Structure Description Function
RibosomesSmall complex assemblies of proteins and RNA, often bound to endoplasmic reticulum
Sites of protein synthesis
EUKARYOTIC ORGANELLES
RIBOSOMEShttp://www.ibri.org/RRs/RR051/51cytoskeleton.gif
http://www.estrellamountain.edu/faculty/farabee/biobk/BioBookCELL2.html#Ribosomes (Both images)
THE CELL THEORYClassical Theory:
Matthius Schleiden and Theodor Schwann (1838)1. All organisms are composed of one or more cells.2. The cell is the basic unit of structure and
organization of living things.3. All cells come from pre-existing cells (through cell
division).
Modern Additions:4. All cells contain hereditary information which is
passed from cell to cell during cell division.5. All cells are basically the same in chemical
composition.6. All energy flow (metabolism and biochemistry) of
life occurs within cells.