J210 Lecture 2 Prokaryotes and EukaryotesSlide 2Slide 3Slide 4Slide 5Slide 6Slide 7Slide 8Slide 9Slide 10Slide 11Slide 12Slide 13FlagellaSlide 15Slide 16Slide 17Slide 18Eukaryotic flagella and cilliaSlide 20Slide 21Slide 22Slide 23Slide 24Slide 25Slide 26Slide 27Slide 28Slide 29Slide 30Slide 31Slide 32Slide 33Slide 34J210 Lecture 2Prokaryotes and EukaryotesEukaryotes/ProkaryotesEukaryotes/ProkaryotesObjectives:1. Be able to describe the different domains of life and naming system.2. Differentiate structural and other features that distinguish prokaryotes from eukaryotes and how this impacts disease and medical treatmentProkaryotes PathogensPathogensProkaryotes - primitive nucleus, no nuclear membrane1. Archaea (domain) (formerly Archaebacteria)•Similar to bacteria. live in harsh environments, such as hot springs and salt lakes, soils, and marshlands.•Archaea are particularly numerous in the oceans•No pathogens known2. Bacteria (domain) (formerly Eubacteria)•PathogensB. Eukaryotes (domain); True nucleus with nuclear membrane•Humans, spider, flies, plants, molds, yeasts, parasites•PathogensPhylogenetic tree with 3 domainsPhylogenetic tree with 3 domainsKingdom When Evolved Structure Prokaryotes:Bacteria 3 to 4 billion years agoUnicellularArchaea 3 to 4 billion years agoUnicellularEukaryotes:Protista 1.5 billion years ago Unicellular Fungi 1 billion years ago Unicellular or MulticellularAnimalia 700 million years ago MulticellularPlantae 500 million years ago MulticellularEukaryotes have organelles or compartments, prokaryotes do notEukaryotes have organelles or compartments, prokaryotes do notStructure of animal cell Structure of animal cellStructure of plant cell Structure of plant cellStructure of Prokaryotic cellsStructure of Prokaryotic cells•The most important organelle for differentiating between eukaryotes and prokaryotes is the nucleus. •Prokaryotes have no nucleus, eukaryotes do (exception, red blood cells)•The most important organelle for differentiating between eukaryotes and prokaryotes is the nucleus. •Prokaryotes have no nucleus, eukaryotes do (exception, red blood cells)•Eukaryotic cells have organelles for specific functions. (See table on slide 5)•Prokaryotes have no organelles•Eukaryotic cells have organelles for specific functions. (See table on slide 5)•Prokaryotes have no organelles•Components of eukaryotic cells which would not be considered organelles•Microtubules and microfilaments•Cytoskeleton structure•Movement by forming pseudopoda•Chromosomes•Packaging of DNA involving histone proteins•Components of eukaryotic cells which would not be considered organelles•Microtubules and microfilaments•Cytoskeleton structure•Movement by forming pseudopoda•Chromosomes•Packaging of DNA involving histone proteinsChromosomes•1 copy in prokaryotes (haploid) and 2 copies in eukaryotes (diploid)•The prokaryotes typically have a single circular chromosomeChromosomes•1 copy in prokaryotes (haploid) and 2 copies in eukaryotes (diploid)•The prokaryotes typically have a single circular chromosomeLocomotion•Cilia–Only in eukaryotes–Motion is in one plane (beating)•Flagella–Both prokaryotes and eukaryotes but note the differences in structure–Motion is rotational in prokaryotes–Motion is by undulation in eukaryotesFlagella–Used for locomotion–Direction is determined by phototaxis or chemotaxis–Eukaryotes•Flagella are internal, entirely surrounded by cytoplasmic membrane•Only found on one pole of cell•Action is a rhythmic undulation which pushes or pulls the cell–Prokaryotes•Flagella are imbedded in cell envelope•Several configurations exist•Action is rotational, cells move by “run and tumble”Configurations:MonotrichousLophotrichous (polar)Amphitrichous (bipolar)PeritrichousProkaryotic FlagellaAnimation: Flagella_arrangeEukaryotic and prokaryotic flagella function differently in their mechanism of propulsion•Eukaryotic flagella whip back & forth (undulate)•Prokaryotic flagella rotate– Process of chemotaxissignal moleculesignal moleculecytoplasmcytoplasmcell wallcell wallflagellumflagellummotor of flagellummotor of flagellumreceptorreceptorAnimation: flagella_movementFlagellin•Many copies of a single protein that make up the filament •Basal body also protein Animation: Flagella_structureBacterial spirochetes have axial fibrils in a sheath. Called axial filaments•Helical/spiral-shaped bacteria are called Spirochetes•The cell corkscrews to moveAxial filamentsAnimation: spirochetesEukaryotic flagella and cillia•Eukaryotic flagella and cillia do not pierce the cell membrane.•Action is in a beating fashion (not rotary as in prokaryotes)Cilia•Cilia are short hair like structures (present only on eukaryotes) which extends from cell and provide locomotion. •Motion is by “beating” back and forth•Functions of cilia:–Locomotion in unicellular organisms–Prevention of lung damage in respiratory tract by pushing out microbes/debrishttp://www.youtube.com/watch?v=xQG3QHMxoTAhttp://www.youtube.com/watch?v=BbI47l2nbDQMotile white blood cells move by use of pseudopoda•White blood cells WBCs (i.e. PMNs) are motile but they crawl by means of the microfilaments and microtubules forming pseudopodspseudopodpseudopodaPMNsBacteriaBacteriaThe ribosome, a key difference between prokaryotes and eukaryotesRibosomes of eukaryotes and prokaryotes are different. •70s vs. 80s s: sedimentation coefficient•Ribosomal RNA and many proteins differ in structure between eukaryotes & prokaryotes•very important when it comes to treatment of bacterial diseases by targeting something that is different from our cellsBacillus (bacilli)i.e. Bacillus anthracis (Anthrax)Coccus (cocci)i.e. Staphylococcus aureus(MRSA infection)Spirochete (spirochetes)i.e. Treponema pallidum(Syphilis)Bacillus (bacilli)i.e. Bacillus anthracis (Anthrax)Coccus (cocci)i.e. Staphylococcus aureus(MRSA infection)Spirochete (spirochetes)i.e. Treponema pallidum(Syphilis)http://www.youtube.com/watch?v=tqOVYpkZ0qsBacterial morphology or shapesBacterial morphology or shapesAggregations of cocciAggregations of cocciStreptococci (chain)eg.Streptococcus pyogenesStreptococci (chain)eg.Streptococcus pyogenesdiplococci stop at one cell division (pair)eg. Neisseria gonorrheadiplococci stop at one cell division (pair)eg. Neisseria gonorrheaStaphylococci (clump)eg. Staphylococcus aureusStaphylococci (clump)eg. Staphylococcus