CELLS!. PROKARYOTIC vs. EUKARYOTIC (prokaryotes vs. eukaryotes) Prokaryotes (bacteria)Eukaryotes ★...

CELLS!

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. EUKAROTECommon Features

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

EUKARYOTES

PLANT vs. ANIMAL

Electron Micrograph

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)


Structure Description FunctionCentrioles(Animal)

Cytoskeleton

Flagella/Cilia(Animal, fungi and

some protists)

Central Vacuole (Plant)

Cell Wall(Plant)

Cytoplasm/Cytosol

Ribosomes


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


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


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


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


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


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


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)


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”)


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



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


MitochondriaPeanut shaped structure with double membrane (outer membrane and highly folded inner membrane called cristae)

“Powerhouse” of the cell; sites of oxidative metabolism


MITOCHONDRIA

http://academic.brooklyn.cuny.edu/biology/bio4fv/page/mito.gif


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


CHLOROPLAST

http://upload.wikimedia.org/wikipedia/commons/4/49/Plagiomnium_affine_laminazellen.jpeg

http://virtualbiologytutor.co.uk/images/chloroplast.jpg


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


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


CENTRIOLES

http://upload.wikimedia.org/wikipedia/commons/4/49/Plagiomnium_affine_laminazellen.jpeg

http://images.protopage.com/view/721389/3ydo50yjpdnqy8ag4flqbd1un.jpg


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


CytoskeletonNetwork of protein filaments

Provides internal structural support; helps in cell movement


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


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.


Flagella/CiliaCellular extensions made up of pairs of microtubules

Aid the cell in locomotion (movement) or feeding


CILIA FLAGELLA

http://img.sparknotes.com/figures/2/2faaa24e75677b6732cd24bf35c357da/flagella.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


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


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


CENTRAL VACUOLE


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


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


Cell WallIn plant cells, outer layer of cellulose; in bacteria, outer layer of protein; also found in fungi and some protists

Protection and support


CELL WALL

http://www.learner.org/courses/essential/life/images/show2.leaf.jpg


http://library.thinkquest.org/C004535/media/cell_wall.gif


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


Cytoplasm/CytosolClear, gelatinous fluid that fills the inside of the cell

Protection and support


CYTOPLASM / CYTOSOL

http://www.cartoonstock.com/lowres/rjo0896l.jpg


http://www2.puc.edu/Faculty/Gilbert_Muth/art0063.jpg


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.


RibosomesSmall complex assemblies of proteins and RNA, often bound to endoplasmic reticulum

Sites of protein synthesis


RIBOSOMEShttp://www.ibri.org/RRs/RR051/51cytoskeleton.gif

http://www.estrellamountain.edu/faculty/farabee/biobk/BioBookCELL2.html#Ribosomes (Both images)

CELL ANALOGIES

FACTORY

CELL ANALOGIES

FACTORY

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.

Date post:	18-Dec-2015
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CELLS!. PROKARYOTIC vs. EUKARYOTIC (prokaryotes vs. eukaryotes) Prokaryotes (bacteria)Eukaryotes ★...

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