Prokaryotes are widespread on Earth

Bacteria

Archaebacteria

Methanogens

• Break down cellulose in a cow’s stomach
• Produce marsh (methane) gas

Extreme Halophiles

• Live in very salty water
• Use salt to generate ATP (energy)
• Dead Sea, Great Salt Lake inhabitants

Thermoacidophiles or Thermophiles

• Live in extremely hot environments
• Found in volcanic vents, hot springs, cracks on ocean floor that leak acid

Clicker Question!

• Have a membrane bound nucleus and organelles:
• A: Prokaryotes
• B: Eukaryotes
• C: Nokaryotes

Bacteria vs Archaebacteria

Bacteria and archaea have similar structures.

• Bacteria and archaea have similar structures.

• flagellum

• pili

• plasmid

• cell wall

• chromosome

• plasma membrance

• This diagram shows the typical structure of a prokaryote. Archaea and bacteria look very similar, although they have important molecular differences.

• plasmid
• flagellum
• pili

Bacteria and archaea have molecular differences.

• Bacteria and archaea have molecular differences.

• GRAM NEGATIVE

• GRAM POSITIVE

• Archaea have different lipids entirely (cell walls lack peptidoglycan)

• The amount of peptidoglycan within the cell wall can differ between bacteria

Gram staining identifies bacteria.

• Gram staining identifies bacteria.

• Gram-negative bacteria have a thin layer of peptidoglycan and stain red.

• Gram-positive bacteria have a thicker peptidoglycan layer and stain purple.

• stains polymer peptidoglycan
• gram-positive stains purple, more peptidoglycan
• gram-negative stains pink, less peptidoglycan