Intro to Prokaryotes Lecture 1 Spring 2014
Meet the Prokaryotes 1
Meet the Prokaryotes 2
Meet the Prokaryotes 3 Why study prokaryotes?
Deep Time 4 Fig. 25.7 Fossilized stromatolite (above) and living stromatolite (below) When did Prokaryotes evolve? Stromatolites rocklike structures of bacteria and sediment
Deep Time 5 How did early prokaryotes produce ATP? Evolution of electron transport systems ~ 3 bya Development of atmospheric oxygen ~ 2.7 bya Fig. 25.7
Deep Time Evolution of eukaryotes~ 2.1 bya 6 Fig. 25.8
The New Tree of Life 7 Phylogeny - the evolutionary history of a species or group of related species Taxonomy Ordered division of organisms into categories
The New Tree of Life 8 Prokaryotes Eukaryotes
The New Tree of Life 9 Fig. 26.21
10 Review 1. Draw an animal cell. Label structures w/name and function 2. Make a list of the differences between plant and animal cells 3. Make a list of the differences between prokaryotes and eukaryotes
Animal cell structures: Plasma membrane Nucleus Cytosol Ribosomes Endoplasmic reticulum Golgi apparatus Mitochondria Cytoskeleton Vacuoles Peroxisome Eukaryotes: Animal Cells 11 Not typically found in plants: Centrosome Lysosomes Flagella See Fig. 6.9 Animal cell
Plant cell structures: Plasma membrane Nucleus Cytosol Ribosomes Endoplasmic reticulum Golgi apparatus Mitochondria Cytoskeleton Peroxisome Eukaryotes: Plant Cells 12 Not found in animals: Cell Wall w/plasmodesmata Plastids (Chloroplasts, Amyloplasts, Chromoplasts) Central vacuole Fig. 4.6 Animal cell See Fig. 6.9 Plant cell
Prokaryotes Bacteria Cannot grow above 100 C Archaea Extremophiles thermophiles halophiles 13
Prokaryotes 14 Prokaryotes: Domain Bacteria & Archaea Unicellular Colonial or solitary Small
Structure: Shapes 15 Prokaryotes can be described by shape coccus, bacillus, spirillum Colonies can be described by how cells are aggregated strepto = in chains e.g., streptobacilli staphylo = in clusters e.g., staphylococci Fig. 27.2 (spirillum)
Structure: Cell Walls 16 Function of cell walls? Eukaryotes Which eukaryotes have cell walls? What is the major structural components for each? Bacteria Peptidoglycan Classification gram-positive and gram-negative Archaea Lack peptidoglycan Contain other polysaccharides & proteins
Structure: Bacterial Cell Walls 17 Lipopolysaccharides. See Fig. 27.3
Gram-positive & Gram-negative 18 Why does this classification matter? Within group of pathogenic (disease-causing) bacteria, gram-negative more threatening than gram-positive.
Gram-positive & Gram-negative 19 Gram-negative Toxic lipopolysaccarides Outer membrane defends bacteria against a body s defense system Antibiotic resistance reduces/prevents drug entry targeted to peptidoglycan layer
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Structures for Attachment 22 Capsules Slime layer Fimbriae Pili Fig. 27.4 Fig. 27.12 Fimbriae Fig. 27.5
Structures for Movement 23 Taxis Fig. 27.6
Structure: Internal Organization 24 Fig. 27.7
Structure: Internal Organization 25 Plasmids a small ring of DNA carrying accessory gene Prokaryotic chromosome Ring - few proteins Fig. 27.8.
Metabolic Diversity 26
Metabolic Diversity: Oxygen 27 Obligate aerobes Obligate anaerobes Fermentation or Anaerobic respiration Facultative anaerobes
28 How can the metabolic capabilities of bacteria help us solve environmental problems? Show movie
29 Toxins in the environment Bioaccummulation Biomagnification
Bioremediation use of biological processes to degrade, transform, and/or remove contaminants from soil and water 30
Phytoremediation 31 Use of plants for on-site treatment of contaminated soils, sediments, and water Hyperaccumulators E.g., cadmium, lead, arsenic, zinc
Phytoremediation 32 Phytoremediaton & genetic engineering Bacteria gene to transform methylmercury
Metabolic Diversity: Unique Capabilities 33 Nitrogen fixation & Denitrification Fig. 54.17
Ecological Roles of Prokaryotes 34 Critical for the survival of life on earth Carbon cycle Oxygen Nitrogen cycle Decomposers Fig. 54,17
Ecological Roles: Symbiotic Relationships between prokaryotes & eukaryotes 35 Mutualism Host = fish Fig. 27.15 Symbiont = bacteria inside fish
Ecological Roles: Mutualism 36 Humans & Bacteroides thetaiotamicron Nitrogen fixing in plants Rhizobium spp. and plants from Legume family