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Chapter 22: Bacteria & Archaea - Coggle Diagram
Chapter 22: Bacteria & Archaea
Prokaryote Structure
Smallest of All Cells
1-5 Micrometers
Shapes
Rods (Bacillus)
Spheres (Coccus)
Spirals (Spirilla)
Unicellular, Chains, or Clusters
Cell Wall
Protects & Prevents Lysis
Bacteria
Peptidoglycan
Outside Plasma Membrane
Archaea
Structural Polysaccharides
Gram Stain
Gram Positive
Purple
Thick PG Layer
Gram Negative
Pink
Outer Lipopolysaccharide Layer
Toxic
Resistant to Drugs & Immune System
Thin PG Layer
No Nuclear Envelope
Capsule & Slime Layer
Adheres Surfaces & Cells Together
Resists Attack from Immune System
Sticky Carbs & Proteins Secreted Outside Cell Wall
Retains Cell Moisture
Nostoc Filaments Held Together by Slime
Fimbriae
Hairlike Protein
Helps Cells Stick to Surfaces & Other Cells
Sex Pilus
Mating Bridge
Pulls Two Bacteria Cells Together for DNA Transfer (Conjugation)
Motility
Taxis
Movement Toward (+) or Away (-) from Stimulus
Chemotaxis
Phototaxis
Geotaxis / Magnetotaxis
Mechanisms
Rotating Flagellum Protein Fibers
Internal Flagella (Spirochetes)
Slime-Gliding
Slime Ejected Through Pores
Organelles
No Membrane-Bound Organelles
No Nucleus (DNA in Nucleoid)
No Microtubules
Some Infolded Plasma Membranes Similar to Mitochondria & Chloroplasts
Aerobic Cellular Respiration
Oxygen-Producing Photosynthesis
Membrane Lipids
Bacteria
Unbranched Hydrocarbons
Archaea
Branched Hydrocarbons (Extremeophiles)
Genetic Diversity
Prokaryote DNA
One Chromosome
Circular
Binding Proteins
No Histones (Some in Archaeans)
Genes for All Vital Functions
Much Less Than Eukaryotes
Plasmids
Extra Tiny DNA Rings With Few Genes
Replicate Independently
Not Essential for Life
Add Diversity (Drug Resistance)
Introns Present in Some Archaea (Rare in Bacteria)
Binary Fission
Two Identical Cells (Except Plasmids, Replicate Independently)
Short Generation Time
Limited by Food, Moisture, Crowding, Temperature
Rapid & Exponential Cloning from One Cell
Mutation Importance
Rare Point Mutations Per Division (1/10,000,000)
High Rate of Cell Division
One Mutation Can Change Phenotype
All Mutations (Except Lethal) Passed to Clones
Selection Favors Best Clones
Recombination
Transduction
Replicates by Lytic Cycle
Phage Capsule Traps Bacterial DNA Instead of Viral DNA
Bacteriophage Virus Injects DNA Into Bacteria
Phage Inserts Bacterial Donor Alleles Into Recipient Chromosome (Recombination)
Conjugation
F Plasmid Conjugation
Transfer of Strand of F Plasmid From F+ Donor to F- Recipient Through Mating Bridge
F- Cell Becomes F+ with F Plasmid
R Plasmids (Antiobiotic Resistance) Transfer Rapidly Through Plasmid Conjugation
High Frequency Recombination (HFR)
Donor's F Factor is Part of Chromosome
Part of F Factor & Part of Chromosome (New Alleles) Transferred from HFR to F- Cell
New Alleles Insert into Recipient Chromosome
F Factor Genes Build Sex Pilus for Mating Bridge
Requires Presence of F Factor in Donor Plasmid or Chromosome
Transformation
Griffith's Experiment
Living R Cells Did Not Kill Mice
Heat-Killed S Cells Did Not Kill Mice
Living S Cells Killed Mice
Heat-Killed S & Living R Cells Killed Mice
DNA Bits from Ruptured Donor Cell Absorbed Directly by Recipient Cells (Horizontal Gene Transfer)
Homologous DNA & New Alleles Exchange with DNA in Chromosome (Recombination)
RNA Polymerase
Bacteria
One Kind
Archaea
Several Kinds
Metabolic & Ecological Diversity
Food Webs
Primary Producers
Autotrophs
Carbon Fixers (Create Organic Molecules)
Base of Aquatic Food Webs
Barophilic (Thrive in High Pressure)
Chemoautotrophs of Hydrothermal Vents
Pyrolobus Fumarii
Black Smoker Hydrothermal Vent at TAG Site
Optimum Growth Temperature 106°C to 121°C
Chemoautolithotrophs
Produces Energy from Inorganic Compounds in Geology & Aqueous Environment
Oxidizes Hydrogen
Fixes Carbon from CO2 in Absence of Light
Chemoheterotrophs
Decomposers
Secreted Enzymes Hydrolyze Dead Material or Wastes
Metabolism Releases Gases (CO2, N, P, K, etc)
Absorptive Feeding
Monomers Enter by Diffusion / Active Transport
Nutritional Modes
Autotrophs
Photoautotrophs
Energy from Light
Carbon from CO2 & HCO3-
Chemoautotrophs
Energy from Inorganic Chemicals
Carbon from CO2 & HCO3-
Heterotrophs
Photoheterotrophs
Energy from Light
Carbon from Organic Compounds
Chemoheterotrophs
Energy from Organic Compounds
Carbon from Organic Compounds
Oxygen & Metabolism
Oxygen Destroys Some Metabolic Pathways
Obligate Anaerobes are Poisoned by O2
Tetanus Bacteria
First Cells Were Obligate Anaerobes
Oxygen Generates More ATP
Facultative Anaerobes
Prefer Oxygen but Use Anaerobic Processes in Absence of Oxygen
Obligate Aerobes
Require Oxygen for Cellular Respiration
Most of Today's Life
Oxygen Revolution
Cyanobacterial Photosynthesis Produced Oxygen ~2.5 BYA
Terrestrial Nostoc & Oscillatoria (Cyanobacteria) Still Major World Oxygen Source
Nitrogen Cycle
Atmosphere is 78% Dinitrogen
Most Cells Need Ammonium (NH4+) or Organic N Compounds
Nitrogen Fixers
Cyanobacteria in Water & Soil
Rhizobium Produces Heme & Plant Produces Globin Protein
Fixation of N2 by Bacteria in Soil or Symbiotic Organism in Roots
Ammonification of Dead Organisms & Waste by Decomposers
Ammonia
Assimilation of NH3 Back to Atmosphere
Nitrification of NH3 by Bacteria
Denitrification of Nitrates (NO3) by Bacteria (Restarts Cycle)
Metabolic Cooperation
Prokaryotes Grow Better Together
Cyanobacteria Make Sugar in Filaments with Heterocysts (Provide N for Growth)
Biofilms (Dental Plaque)
Symbiosis
Two Species Living in Close Relationship (Not Free-Living)
Parasitism
Smaller Parasite Benefits at Expense of Host
Pathogens Causing Diseases (Anthrax, Cholera)
Commensalism
One Species Benefits Without Impact on Other
Most Bacteria on Skin
Mutualism
Both Species Benefit from Each Other
Rhizobium Provide Fixed Nitrogen
Legume Roots Provide Sugar & Water
Prokaryotes & Humans
Mutualistic Bacteria
Maintain Normal Colon Function
Ward off Pathogenic Bacteria
Produce Vitamins
Activate Immune System
Found in Digestive Tract
Pathogenic Bacteria
Infections Produce Bacterial Poisons
Secrete Exotoxins
Attack Cell Signal Receptors
Botulism Causes Food Poisoning
Clostridium Tetani (Tetanus) Causes Uncontrolled Spasms of Voluntary Muscles
Botox Causes Muscle Paralysis
Surrounded by Endotoxins
Toxic Outer Membrane of Gram- Bacteria
Salmonella Food Poisoning
Protection
Sanitation is Best Defense
Immunization Preps Immune System to Fight Bacteria
Antibiotics Kill Bacteria Cells, Not Eukaryotes
Penicillin Affects PG Wall
Human Use
Basic Research on Cells & DNA
DNA Technology & Genetic Engineering
Commercial Chemical & Drug Production
Bioremediation
Sewage Treatment
Environmental Cleanup
Food Products
Yogurt
Cheese
Archaeans Closer to Eukaryotes Than Bacteria
Domain Bacteria
Proteobacteria
Gram-Negative
Diverse Metabolism & Nutrition
N-Cycle Bacteria & Gastrointestinal Parasites
Escherichia Coli
Salmonella
Vibrio Choleri
Chlamydias
Endoparasites
Chlamydia Trachomatis
Preventable & Curable STD
Blindness in Children of Infected Women
Pelvic Inflammatory Disease & Infertility
Gram-Negative
Spirochetes
Spiral Shape
Free-Living or Disease-Causing
Syphilis STD
Treponema Pallidum
Gram-Negative
Lyme Disease
Borrelia Burgdorferi) from Deer Tick & Mice
Cyanobacteria
Plant-Like
Oxygen-Generating Photosynthesis
Nitrogen Fixation
Toxic Blooms
Gram-Negative
Gram-Positive
Decomposers (Source of Antibiotics)
Pathogens
Anthrax
Bacillus Anthracis
Tetanus
Clostridium Tetani
Staph
Staphylococcus Aureus
Methicillin-Resistant Staphylococcus Aureus (MRSA)
Strep
Streptococcus
TB
Mycobacterium Tuberculosis
Leprosy
Mycobacterium Leprae
Domain Archaea
Extremophiles
Halophiles
Double to Triple Seawater
Up to 20% Salinity
Thermophiles
At or Close to Boiling Point
Methanogens
Produce Methane (CH4) as By-Product of Anaerobic Respiration
Normal-Condition Archaea
No Human-Disease-Causing Archaeans