Domains of Life

Domains: A New Taxa 1996: Proposed by Carl Woese and George Fox

Domains

The Prokaryotes

Prokaryotes Single-celled organisms that lack membrane-bound organelles

Prokaryotes Smallest living organisms Found living everywhere on Earth Some are: heterotrophs, autotrophs, chemotrophs

Roles of Prokaryotes Pathogens: Decomposers:

Roles of Prokaryotes

Roles of Prokaryotes Live in the intestines of animals Mutualistic relationship: How do both organisms benefit? Live in soil and “fix” nitrogen What type of relationship is this?

Roles of Prokaryotes

Roles of prokaryotes Used in food production Most recently, bacteria have been utilized for their ability to produce chemicals

Kingdoms of Prokaryotes Split into: Eubacteria (true bacteria) Archaea (ancient organisms)

Eubacteria Capsule: Cell wall: Peptidoglycan Historically, bacteria were classified based on whether their cell wall turned color when the bacteria was stained in the Gram staining protocol

Eubacteria Chromosome: Nucleoid region: Plasmid: Flagellum and Pili:

Eubacterial shapes

Eubacterial Metabolism Aerobes: Anaerobes:

Eubacterial Metabolism Obligate vs. Facultative

Types of Eubacteria The autotrophs: Know table on page 48 of textbook

Types of Eubacteria The autotrophs: Purple bacteria (proteobacteria)

Types of Eubacteria The autotrophs: Green bacteria

Types of Eubacteria The autotrophs: Blue-green algae (cyanobacteria)

Types of Eubacteria The heterotrophs Gram-positive bacteria

Types of Eubacteria The heterotrophs Spirochetes

Types of Eubacteria The heterotrophs Chlamydias

Cell Division Cells divide by binary fission During binary fission, describe what happens to the cell and what happens to the DNA?

Cell Division Cells divide by binary fission Mutations? What are they?

Increasing Genetic Diversity Conjugation: Transformation: Role of these?

Archaea Extremophiles

Types of Archaea Methanogens

Types of Archaea Halophiles

Types of Archaea Thermophiles

Types of Archaea Psychrophiles

Homework To be completed for Monday, Oct 14. 1) Believe it or not, pathogens are a required part of a healthy ecosystem. What role(s) do pathogens play in the environment? 2) List out 5-10 other roles that prokaryotes play in the environment. Textbook: Read pages 44-53. Do problems 6-10 on page 53.