Micro & Lab Intro.pptx

Microbiology  The study of organisms too small to be seen without magnification  Microorganisms include: – Bacteria – Viruses – Fungi – Protists Algae Protozoa – Helminths (worms) – Archaea...

Microbiology  The study of organisms too small to be seen without magnification  Microorganisms include: – Bacteria – Viruses – Fungi – Protists Algae Protozoa – Helminths (worms) – Archaea 1  Size of Microbes Millimeter (mm) Micrometer (um) Nanometer (nm) 2  Evolutionary Timeline Origins of Microorganisms  Bacteria-like organisms have existed on earth for about 3.5 billion years – Prokaryotes (pre-nucleus): Simple cells – Eukaryotes (true nucleus): Complex cells 3  Cells vs Viruses  Prokaryotes lack nucleus and organelles  Eukaryotes contain nucleus and organelles  Viruses aren’t Proks or Euks – not a cell!  Parasitic particle made of nucleic acid and protein  Complex molecule or primitive acellular organism? 4  3 Domains of Life  Discovered 3 very different types of organisms on Earth based on DNA & RNA  Bacteria – true prok. bacteria that have peptidoglycan  Archaea – odd proks that live in extreme environments, high salt, heat, ph, acid, pressure..  Eukarya – euks have a nucleus and organelles 5  Bacteria Characteristics:  Prokaryotic Cell  Unicellular  No organelles  No nucleus  Single circular chromosome (DNA)  70S Ribosomes  Size 1-5 micrometers  Some Motile  Some photosynthetic  Peptidoglycan in cell wall  Found in every habitat  Archaea Characteristics:  Prokaryotic Cell  Unicellular  No nucleus or organelles  Single circular chromosome (DNA)  70S Ribosomes  Size most under 1 micrometer  Some Motile  Not photosynthetic  No peptidoglycan  Unique features in their tRNA, cell membrane, cell wall – own Domain  Extremophiles - found in extreme environments: hot springs, high salt, acidic, arctic cold, anaerobic, etc  Fungus Characteristics:  Eukaryotic Cell  Organelles  Nucleus  Multiple linear chromosomes (DNA)  80S Ribosomes  Size varies - few micrometers (yeast), to few centimeters (mold), to miles (mushroom)  Unicellular to Multicellular  Not Motile  Not photosynthetic  Heterotrophic  Cell wall contains chitin  Found widespread on land especially in soil, plant matter  Animal-like Protists – Protozoa Characteristics:  Eukaryotic Cell  Organelles  Nucleus  Multiple linear chromosomes (DNA)  80S Ribosomes  Size: 10~150 micrometers  Always Unicellular  Motile  Most are not photosynthetic  Complex life cycle  Found in soil & water  No cell wall  Plant-like Protists – Algae Characteristics:  Eukaryotic Cell  Organelles  Nucleus  Multiple linear chromosomes (DNA)  80S Ribosomes  Found in water, moist habitats  Photosynthetic w/ chloroplasts  Size varies greatly: micrometer to hundreds feet (kelp)  Unicellular to multicellular  Some motile/some nonmotile  Cell wall type varies - all have one!  Helminths Characteristics:  Eukaryotic Cell  Organelles  Nucleus  Multiple linear chromosomes (DNA)  80S Ribosomes  Worm-like parasites (Animals!)  Size: millimeter to meter (or more)  Multicellular complex organisms w/mouthparts for attachment, reproductive & digestive organs  Motile  No cell wall, not photosynthetic  Found in human & animal intestinal tract, urinary, bloodstream, soil  Viruses Characteristics:  Not a Cell  No Nucleus, No Organelles, No Ribosomes or Inclusions  Has protein coat called capsid  Has nucleic acid - DNA or RNA  Infectious particle  Size: tiniest range 20-200 nanometers (nm)  Requires host cell (to replicate)  Not Motile, not photosynthetic, doesn’t grow, eat, produce food or waste, respond to stimuli, etc  Found in every habitat on earth