Presentation on theme: "Biology: life study of What is Life? Cellular Structure: the unit of life, one or many Growth: cell enlargement, cell number Evolution: long term adaptation."— Presentation transcript:
Biology: life study of What is Life? Cellular Structure: the unit of life, one or many Growth: cell enlargement, cell number Evolution: long term adaptation Behavior: short term response to stimuli Reproduction: avoid extinction at death Metabolism: photosynthesis, respiration, fermentation, digestion, gas exchange, secretion, excretion, circulation--processing materials and energy Movement: intracellular, movement, locomotion Properties of Life
Scanning Electron Microscope (SEM) image..the shape?
? ? Transmission Electron Microscope (TEM) image..the shape?
Sulfolobus acidocaldarius 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 TEM or SEM? Of Archaeon Shape?
Bacterium of the Genus: Leptospira TEM or SEM?Shape?
Vibrio cholerae Helicobacter pylori What are the shapes of these disease bacteria? Are they motile? If so, by what mechanism?
Cell Structure: Movement anchorage rotation basal rings and rod stiff helical flagellum is rotated by motor apparatus in the membrane by H+ ATPase at rates of rps (>12,000 rpm!) hook directional rotation? flagellin protein 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)) Taxis: movement toward stimulus 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 billion years!
Cell Structure: Nucleoid transcription by RNA polymerase one circular DNA molecule no histone protein association attached to cell membrane separation of chromosomes replication by DNA polymerase Nucleoid - genome translation of mRNA into protein rRNA + protein + ribozymes 70S Ribosome cytokinesis by furrowing Process called binary fission NOT mitosis! Genome and copy are identical Genome is haploid There is no synapsis There is no recombination
How Many Kingdoms? Multicellular Animals MyxozoansProtozoans Tracheophytes Bryophytes True Fungi Slime Molds Red algae Brown Algae Green Algae Chrysophytes EuglenoidsArchezoans Archaea Bacteria Original Cell Extant Extinct Cyanobacterium endosymbiosis Eukaryotes ARE Chimeras! Eubacterium endosymbiosis Though sketched here as single events, these endosymbioses were very likely multiple events!
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: 1.Archaeamoebae/Pelobiontida (Pelomyxa) 2.Metamonada (Giardia) 3.Microsporidia
Uroid Glycogen body Vacuoles Pseudopodia Endosymbiotic bacteria Pelomyxa palustris Free-living in freshwater sediment (microaerophilic) Phagocytosis active At least 3 species of endosymbiont in each cell…two species are methanogenic archaeons! Anterior uroid (macropseudopodium) for amoeboid movement Smaller pseudopodia do not enlarge Accumulate glycogen reserves
pelomyxapalustris.html uk.org.uk/micropolitan/fresh/protozoa/frame3.html Reproduction: Nuclei Daughter Amoeba Mitosis of nucleus Cytokinesis by furrowing What would you suggest has been a large component of this individuals phagocytosis diet?
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 wood particles and bacteria nucleus
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: 1.Kinetoplasta (Trypanosoma gambiense) sleeping sickness 2.Euglenoida (Euglena) photosynthetic, chlorophyll a,b, paramylum
Euglena gracilis Nucleus Eyespot Anterior invagination With internal short flagellum Long flagellum rooted here also (not shown) Paramylon grain Chloroplasts Protein pellicle (striations) Posterior extension Contractile vacuole Pyrenoid Mitochondrion
Though sketched here as single events, these endosymbioses were very likely multiple events! How Many Kingdoms? Multicellular Animals MyxozoansProtozoans Tracheophytes Bryophytes True Fungi Slime Molds Red algae Brown Algae Green Algae Chrysophytes EuglenoidsArchezoans Archaea Bacteria Original Cell Extant Extinct Cyanobacterium endosymbiosis Eukaryotes ARE Chimeras! Eubacterium endosymbiosis Euglenoid mitochondria are unique! For euglenoids, the chloroplast is a secondary endosymbiosis. Chlorophyte algal endosymbiosis
How Many Kingdoms? Multicellular Animals MyxozoansProtozoans Tracheophytes Bryophytes True Fungi Slime Molds Red algae Brown Algae Green Algae Chrysophytes EuglenoidsArchezoans Archaea Bacteria Original Cell Extant Extinct Cyanobacterium endosymbiosis Eukaryotes ARE Chimeras! Eubacterium endosymbiosis For brown algae, the chloroplast is also a secondary endosymbiosis. Chlorophyte algal endosymbiosis rer rough ER nucleomorph phaeoplast
Vacuole -toxic waste processing Eukaryotic Cell Structure Middle Lamella-pectin glue Cell Membrane-phospholipid -transport proteins Cytosol-enzymes for -fermentation -glycolysis Nucleus-DNA linear histone bound -transcription -replication Endoplasmic Reticulum -internal transport 80S Ribosomes -protein synthesis -translation Golgi Apparatus -sorting -packaging Vesicles -import/export package Mitochondria -respiration 70S ribosomes naked, circular DNA Cell Wall-cellulose+protein Chloroplast -photosynthesis 70S ribosomes naked, circular DNA Other eukaryotic organelles have been omitted here!
cell wall cellulose + protein + wax chloroplast photosynthetic endosymbiont nucleus RNA transcription, DNA replication vacuole toxic waste processing cytosol fermentation, glycolysis, etc. gas space cooling and gas exchange TEM, SEM, Light Microscopy? Protist, Plant, Animal, Fungus? Natural or Artificial Coloring?
TEM or SEM? of a Plant or Animal Cell?
Cell: a mesophyll protoplast cell membrane import/export chloroplast photosynthesis cytosol fermentation glycolysis vacuole toxic waste processing nucleus transcription replication natural or artificial coloring? ? TEM, SEM, or Light? (Cell wall was digested off by cellulase)