Presentation on theme: "Biology: What is Life? life study of Properties of Life"— Presentation transcript:
1 Biology: What is Life? life study of Properties of Life Cellular Structure: the unit of life, one or manyMetabolism: photosynthesis, respiration, fermentation, digestion, gas exchange, secretion, excretion, circulation--processing materials and energyGrowth: cell enlargement, cell numberMovement: intracellular, movement, locomotionReproduction: avoid extinction at deathBehavior: short term response to stimuliEvolution: long term adaptation
6 Scanning Electron Microscope (SEM) image..the shape?
7 ? ? Transmission Electron Microscope (TEM) image..the shape?
8 Sulfolobus acidocaldarius TEM or SEM? Of ArchaeonExtremophileSulfur metabolismpH 1 to 675°C OptimumStrict aerobePartial monolayer (C40) membranesMultiple DNA CirclesIntrons in DNADNA binding proteinsrRNA similarityRNA synthase similarityOperon style regulation70S ribosomesShape?
9 Bacterium of the Genus: Leptospira TEM or SEM?Shape?Bacterium of the Genus: Leptospira
10 What are the shapes of these disease bacteria? Vibrio choleraeHelicobacter pyloriAre they motile?If so, by what mechanism?
11 Cell Structure: Movement hookdirectional rotation?basal rings and rodanchoragerotationstiff helical flagellumflagellin proteinis rotated by “motor apparatus”in the membrane by H+ ATPaseat rates of rps(>12,000 rpm!)Taxis:movement toward stimulusExceptions: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 lightchemotaxis:movement to chemicals
12 Prokaryotic Growth Cells are generally very small Cells may double in size but only before binary fissionGrowth mostly in terms of cell number or colony size, etc.Doubling time in cell numbers may be 20 minutes in ideal conditionsCould quickly take over the earth if conditions could remain idealVery competitive in ideal environmentsUltimate survivors billion years!
13 Cell Structure: Nucleoid Nucleoid - genomeone circular DNA moleculeno histone protein associationattached to cell membranetranscription by RNA polymerasereplication by DNA polymeraseseparation of chromosomescytokinesis by furrowing70S RibosomeProcess called binary fissionNOT mitosis!Genome and copy are identicalGenome is haploidThere is no synapsisThere is no recombinationrRNA + protein + ribozymestranslation of mRNA into protein
23 How Many Kingdoms? Extant Eukaryotes ARE Chimeras! Extinct Multicellular AnimalsMyxozoansProtozoansTracheophytesBryophytesTrue FungiSlime MoldsRed algaeBrown AlgaeGreen AlgaeChrysophytesEuglenoidsArchezoansArchaeaBacteriaEukaryotes ARE Chimeras!CyanobacteriumendosymbiosisExtinctEubacteriumendosymbiosisThough sketched here as single events, these endosymbioses were very likely multiple events!Original Cell
24 Archezoans “Protozoan parasites without mitochondria or Golgi” Oldest nucleated cellsDiverged from other Eukaryotes 2bybp… prior to ER and Golgi evolutionLack peroxisomesRibosomes are 70S but NOT 80S400 species (many more likely unknown parasites!)Three phyla:Archaeamoebae/Pelobiontida (Pelomyxa)Metamonada (Giardia)Microsporidia
25 Pelomyxa palustris Pseudopodia Endosymbiotic bacteria Free-living in freshwater sediment (microaerophilic)Phagocytosis activeUroidAccumulate glycogen reservesAt least 3 species of endosymbiont in each cell…two species are methanogenic archaeons!Glycogen bodyAnterior uroid (macropseudopodium) for amoeboid movementVacuolesSmaller pseudopodia do not enlarge
26 Reproduction: Mitosis of nucleus Cytokinesis by furrowing Nuclei “Daughter” AmoebaWhat would you suggest has been a large component of this individual’s phagocytosis diet?
27 wood particles and bacteria TrichonymphaTermite gut protist symbiont lacking mitochondriaProtist has bacterial endosymbionts making cellulase for digesting wood particles taken in by phagocytosisAnd spirochete ectosymbionts for motilityspirochetesnucleuswood particles and bacteria
28 Euglenozoa Flagellated protists which can be photosynthetic Odd featuresProtein pellicle instead of cell wallOdd mitochondria (discoid cristae) so unique endosymbiontChromosomes remain condensed during interphase400 species (many more likely unknown parasites!)Two sub-phyla:Kinetoplasta (Trypanosoma gambiense) sleeping sicknessEuglenoida (Euglena) photosynthetic, chlorophyll a,b, paramylum
30 How Many Kingdoms? Extant Euglenoid mitochondria are unique! Multicellular AnimalsMyxozoansProtozoansTracheophytesBryophytesTrue FungiSlime MoldsRed algaeBrown AlgaeGreen AlgaeChrysophytesEuglenoidsArchezoansArchaeaBacteriaChlorophytealgalendosymbiosisEuglenoid mitochondria are unique!Eukaryotes ARE Chimeras!CyanobacteriumendosymbiosisFor euglenoids, the chloroplast is a secondary endosymbiosis.ExtinctEubacteriumendosymbiosisThough sketched here as single events, these endosymbioses were very likely multiple events!Original Cell
31 How Many Kingdoms? Extant Eukaryotes ARE Chimeras! Extinct rough ER Multicellular AnimalsMyxozoansProtozoansTracheophytesBryophytesTrue FungiSlime MoldsRed algaeBrown AlgaeGreen AlgaeChrysophytesEuglenoidsArchezoansArchaeaBacteriaChlorophytealgalendosymbiosisFor brown algae, the chloroplast is also a secondary endosymbiosis.rerEukaryotes ARE Chimeras!CyanobacteriumendosymbiosisExtinctEubacteriumendosymbiosisrough ERnucleomorphphaeoplastOriginal Cell
34 Protist, Plant, Animal, Fungus? TEM, SEM, Light Microscopy?Natural or Artificial Coloring?cell wallcellulose + protein + waxchloroplastphotosynthetic endosymbiontnucleusRNA transcription, DNA replicationvacuoletoxic waste processingcytosolfermentation, glycolysis, etc.gas spacecooling and gas exchange
36 ? Cell: a mesophyll protoplast (Cell wall was digested off by cellulase)TEM,SEM, orLight?cell membraneimport/exportchloroplastphotosynthesis?nucleustranscriptionreplicationvacuoletoxic waste processingcytosolfermentation glycolysisnatural or artificial coloring?