Biology: What is Life? life study of Properties of Life Cellular Structure: the unit of life, one or many Metabolism: photosynthesis, respiration, fermentation, digestion, gas exchange, secretion, excretion, circulation--processing materials and energy Growth: cell enlargement, cell number Movement: intracellular, movement, locomotion Reproduction: avoid extinction at death Behavior: short term response to stimuli Evolution: long term adaptation

Cell Structure Prokaryotic before nucleus Eukaryotic true nucleus

Comparing Cell Sizes Mycoplasma 0.3-0.8 µm E. coli 1x2 µm Cyanobacteria 10 µm diam Plant Cell 30x75 µm Obviously eukaryotic Nucleus present Mitochondrion  Bacterium Chloroplast  Cyanobacterium

Cell Structure: Boundary Mycoplasma Water and enzymes for fermentation, glycolysis, Kreb’s cycle, Calvin cycle, naked circular DNA for transcription, 70S ribosomes for translation cell membrane bilayer glycolipid, sulfolipid transport proteins cytosol regulates input/output ETS for PSN, Resp Gram Positive Gram Negative cell wall-murein peptidoglycan muramic acid - peptide prevents dye release prevents bursting turgor pressure penicillin sensitive additional membrane bilayer glyco- sulfo-lipids releases dye

Prokaryotic Cell Shapes Coccus - cocci Bacillus - bacillus Spirillum - spirilli Vibrio - vibrios

Scanning Electron Microscope (SEM) image..the shape? http://www.up.ac.za/academic/electron/bacteria.jpg

? ? Transmission Electron Microscope (TEM) image..the shape? http://library.thinkquest.org/3564/Cells/cell91.gif

Sulfolobus acidocaldarius TEM or SEM? Of Archaeon Extremophile Sulfur metabolism pH 1 to 6 75°C Optimum Strict aerobe Partial monolayer (C40) membranes Multiple DNA Circles Introns in DNA DNA binding proteins rRNA similarity RNA synthase similarity Operon style regulation 70S ribosomes http://dac.molbio.ku.dk/Sulfolobus.jpg Shape?

Bacterium of the Genus: Leptospira TEM or SEM? Shape? Bacterium of the Genus: Leptospira http://phil.cdc.gov/PHIL_Images/02142002/00001/PHIL_138.tif

What are the shapes of these disease bacteria? http://www.designthatmatters.org/proto_portfolio/cholera_treatment/multimedia/vibrio_cholerae.jpg Vibrio cholerae Helicobacter pylori Are they motile? If so, by what mechanism? http://helico.gsnu.ac.kr/

Cell Structure: Movement hook directional rotation? basal rings and rod anchorage rotation stiff helical flagellum flagellin protein is rotated by “motor apparatus” in the membrane by H+ ATPase at rates of 200-1700 rps (>12,000 rpm!) Taxis: movement toward stimulus Exceptions: myxomycetes, some cyanobacteria use slime, but how? spirochetes have flexible internal microtubules (endosymbiotic source of flagella in eukaryotes?) ((gut parasite in termites have spirochete symbiosis)) phototaxis: movement toward light chemotaxis: movement to chemicals

Prokaryotic Growth Cells are generally very small Cells may double in size but only before binary fission Growth mostly in terms of cell number or colony size, etc. Doubling time in cell numbers may be 20 minutes in ideal conditions Could quickly take over the earth if conditions could remain ideal Very competitive in ideal environments Ultimate survivors - 3.5 billion years!

Cell Structure: Nucleoid Nucleoid - genome one circular DNA molecule no histone protein association attached to cell membrane transcription by RNA polymerase replication by DNA polymerase separation of chromosomes cytokinesis by furrowing 70S Ribosome Process called binary fission NOT mitosis! Genome and copy are identical Genome is haploid There is no synapsis There is no recombination rRNA + protein + ribozymes translation of mRNA into protein

Cell Associations ? Coccus Diplococcus Streptococcus - filamentous Staphylococcus - colonial ? Streptobacillus

What shapes and associations are shown in these SEMs? http://www.hhs.gov/asphep/presentation/images/bacteria.jpg

An artificially colored TEM of a cyanobacterium. Thylakoids contain chlorophyll a (green) Metabolism? Association? Shape? http://www.jgi.doe.gov/JGI_microbial/images/microbes2003/anava.jpg

Anabaena --a cyanobacterium w/ division of labor Vegetative Cells (Photosynthesis) Akinete (hypnospore) Heterocyst (N2 fixation) http://www.ac-rennes.fr/pedagogie/svt/photo/microalg/anabaena.jpg

Cyanobacterial Vegetative Cell (photosynthesis) cell wall mesosome cell membrane cyanophycean starch cyanophycin vacuole lipid droplet polyphosphate granule thylakoids nucleoid polyhedral body http://www.botany.hawaii.edu/faculty/webb/BOT311/Cyanobacteria/CBDivideTEM.jpg

Cyanobacterial Heterocyst (N2 fixation) cell wall O2 block cell membrane nucleoid mesosome ETS for O2 reduction cytosol Nitrogenase reduces N2 (requires anaerobic conditions) pore in wall fuel input for respiration http://www.botany.hawaii.edu/faculty/webb/BOT311/Cyanobacteria/Heterocyst.jpg

Cyanobacterial Akinete (hypnospore) cell wall cell membrane cyanophycean starch polyhedral body lipid droplet polyphosphate granule vacuole cyanophycin thylakoids nucleoid http://www.botany.hawaii.edu/faculty/webb/BOT311/Cyanobacteria/AkineteEMBlue400.jpg

Germinating akinetes (producing vegetative filaments) http://www-cyanosite.bio.purdue.edu/images/lgimages/oreg4.jpg

Cell Structure Prokaryotic before nucleus Eukaryotic true nucleus

How Many Kingdoms? Extant Eukaryotes ARE Chimeras! Extinct Multicellular Animals Myxozoans Protozoans Tracheophytes Bryophytes True Fungi Slime Molds Red algae Brown Algae Green Algae Chrysophytes Euglenoids Archezoans Archaea Bacteria Eukaryotes ARE Chimeras! Cyanobacterium endosymbiosis Extinct Eubacterium endosymbiosis http://www.stockhillhouse.co.uk/griffon.jpg Though sketched here as single events, these endosymbioses were very likely multiple events! Original Cell

Archezoans “Protozoan parasites without mitochondria or Golgi” Oldest nucleated cells Diverged from other Eukaryotes 2bybp… prior to ER and Golgi evolution Lack peroxisomes Ribosomes are 70S but NOT 80S 400 species (many more likely unknown parasites!) Three phyla: Archaeamoebae/Pelobiontida (Pelomyxa) Metamonada (Giardia) Microsporidia

Pelomyxa palustris Pseudopodia Endosymbiotic bacteria Free-living in freshwater sediment (microaerophilic) Phagocytosis active Uroid Accumulate glycogen reserves At least 3 species of endosymbiont in each cell…two species are methanogenic archaeons! Glycogen body Anterior uroid (macropseudopodium) for amoeboid movement Vacuoles Smaller pseudopodia do not enlarge http://www.btinternet.com/~stephen.durr/pelomyxapalustris.html

Reproduction: Mitosis of nucleus Cytokinesis by furrowing Nuclei “Daughter” Amoeba http://www.btinternet.com/~stephen.durr/pelomyxapalustris.html What would you suggest has been a large component of this individual’s phagocytosis diet? http://www.microscopy-uk.org.uk/micropolitan/fresh/protozoa/frame3.html

wood particles and bacteria Trichonympha Termite gut protist symbiont lacking mitochondria Protist has bacterial endosymbionts making cellulase for digesting wood particles taken in by phagocytosis And spirochete ectosymbionts for motility spirochetes nucleus wood particles and bacteria http://www.microscopy-uk.org.uk/mag/imgmar03/Trichonympha755.jpg

Euglenozoa Flagellated protists which can be photosynthetic Odd features Protein pellicle instead of cell wall Odd mitochondria (discoid cristae) so unique endosymbiont Chromosomes remain condensed during interphase 400 species (many more likely unknown parasites!) Two sub-phyla: Kinetoplasta (Trypanosoma gambiense) sleeping sickness Euglenoida (Euglena) photosynthetic, chlorophyll a,b, paramylum

Euglena gracilis Posterior extension Mitochondrion Pyrenoid Nucleus Chloroplasts Paramylon grain http://bio.rutgers.edu/euglena/ Protein pellicle (striations) Contractile vacuole Eyespot Anterior invagination With internal short flagellum Long flagellum rooted here also (not shown) http://www.ac-rennes.fr/pedagogie/svt/photo/microalg/euglena.jpg

How Many Kingdoms? Extant Euglenoid mitochondria are unique! Multicellular Animals Myxozoans Protozoans Tracheophytes Bryophytes True Fungi Slime Molds Red algae Brown Algae Green Algae Chrysophytes Euglenoids Archezoans Archaea Bacteria Chlorophyte algal endosymbiosis Euglenoid mitochondria are unique! Eukaryotes ARE Chimeras! Cyanobacterium endosymbiosis For euglenoids, the chloroplast is a secondary endosymbiosis. Extinct Eubacterium endosymbiosis Though sketched here as single events, these endosymbioses were very likely multiple events! http://bio.rutgers.edu/euglena/ Original Cell

How Many Kingdoms? Extant Eukaryotes ARE Chimeras! Extinct rough ER Multicellular Animals Myxozoans Protozoans Tracheophytes Bryophytes True Fungi Slime Molds Red algae Brown Algae Green Algae Chrysophytes Euglenoids Archezoans Archaea Bacteria Chlorophyte algal endosymbiosis For brown algae, the chloroplast is also a secondary endosymbiosis. http://tolweb.org/tree/ToLimages/nucleomorph.jpg rer Eukaryotes ARE Chimeras! Cyanobacterium endosymbiosis Extinct Eubacterium endosymbiosis rough ER nucleomorph phaeoplast Original Cell

Comparing Cell Sizes Mycoplasma 0.3-0.8 µm E. coli 1x2 µm Cyanobacteria 10 µm diam Plant Cell 30x75 µm Obviously eukaryotic Nucleus present Mitochondrion  Bacterium Chloroplast  Cyanobacterium

Eukaryotic Cell Structure Middle Lamella-pectin glue Cell Wall-cellulose+protein Cell Membrane-phospholipid -transport proteins Chloroplast -photosynthesis 70S ribosomes naked, circular DNA Cytosol-enzymes for -fermentation -glycolysis Mitochondria -respiration 70S ribosomes   naked, circular DNA    Nucleus-DNA linear histone bound -transcription -replication Vacuole -toxic waste processing Endoplasmic Reticulum -internal transport 80S Ribosomes -protein synthesis -translation Vesicles -import/export package Golgi Apparatus -sorting -packaging Other eukaryotic organelles have been omitted here!

Protist, Plant, Animal, Fungus? TEM, SEM, Light Microscopy? Natural or Artificial Coloring? cell wall cellulose + protein + wax chloroplast photosynthetic endosymbiont nucleus RNA transcription, DNA replication vacuole toxic waste processing http://gecko.gc.maricopa.edu/~lsola/Leaf/Leafxs.jpg cytosol fermentation, glycolysis, etc. gas space cooling and gas exchange

TEM or SEM? of a Plant or Animal Cell? http://faculty.uca.edu/~johnc/Chloroplast_and_microbodies.jpg

? Cell: a mesophyll protoplast (Cell wall was digested off by cellulase) TEM, SEM, or Light? cell membrane import/export chloroplast photosynthesis ? nucleus transcription replication vacuole toxic waste processing cytosol fermentation glycolysis natural or artificial coloring? http://www.botany.wisc.edu/images/mesophyll-protoplast_lg.jpg

? ? ? Protist, Plant, Animal, Fungus? endoplasmic reticulum http://www.tmd.ac.jp/artsci/biol/textbook/nucleus.gif endoplasmic reticulum internal transport ? 80S ribosome translation nucleus transcription, replication RNA ? ? DNA cytosol fermentation, glycolysis zymogen granule protein storage enzyme secretion mitochondrion respiration

Saccharomyces: yeast from kingdom? Fungi Mitosis nearly complete Cytokinesis via furrowing (budding!) ? ? Cell wall: chitin not cellulose ? ? http://www.jhu.edu/iic/Yeast_1.png