Ch27 Bacteria & Archaea

• Prokaryotic-Lack nucleus
• More resistant to heat and other extreme
• Found in moderate conditions

• Occupy habitats with very high salt content, acidity or methane levelsm or high temperatures.
• Methanopyrus grows in deep sea thermal vents at 98 C-Hyperthermophile
• Sulfolobus grows in hot springs at pH 3
• Halophiles

• 50 or so bacterial phyla-Structural and metabolic features of half unknown
• Some are extremeophiles but many more bacteria favor moderate conditions
• Form symbiotic relationships with eukaryotes

• Photosynthetic bacteria abundant in fresh waters, oceans and wetlands and on surface of arid soils
• Named for blue-green (cyan) color
• Only prokaryotes that generate
• Gave rise to plastids of eukaryotic algae and plants
• Display greates structual diversity found among bacterial phyla
• Essential ecological roles in producing organic carbon and fixing nitrogen

likely arose in an ancient archaeal organism

orginated from proteobacteria and cyanobacteria by endosymbiosis

• Share small size, rapid growth and simple cellular structure
• Are 1-5um in diameter
• limits the amt of materials that can be stored within cells but allows faster cell division

• Spheres- cocci
• Rods- bacilli
• Comma-Shaped- vibrios
• Spiral-shaped Spirochaetes r flexible & spirilli r rigid

Some occur as single cells, pairs and filaments

• Sometimes called Glycocalyx
• Composed of polysacc., protein or both
• Secreted from cells

• Fxn: Evade host defenses
• Hold colony together

• Most hv rigid cell wall outside the PM
• Maintain cell shape and help protect agant attack
• Help to avoid lysis in hypotonic soltion

Archaea and some bacteria use protein where as most bacteria use peptidoglycan

• Thick peptidoglycan layer
• Purple dye held in thick layer
• Cells are stained purple
• Vulnerable to pencillin that interferes in cell wall synethesis

• Less peptidoglycan and a thin outer envelope of lipopolysac.
• Lose purple stain but retain final pink stain
• Cells are stained pink
• Resists pencillin and requires other antibios'

• Move to favorable conditions
• Respond to chemical signals

Switch, twitch, glide or adjust floatation

• Swimming
• Different in eukaryotic flagella
• Like an outboard boat motor
• Differ in number and location of flagella

• Twitch or glide across surface
• Threadlike cell surface structures
• Play import roles in bacterial reprod and dz processes

divide by splitting in two

• Found in aquatic filamentous cyanbact
• Develop when winter approaches
• Survive winter and produce new filaments in spring

• Tough protein coat
• Amazingly long dormant span
• Found in some Gram-pos bacteria

IE: Bacillus antracis, Clostridium botulinum, Clostridium tetani

• Transduction: Via viral vector
• Transformation: Via uptake of DNA from environment
• Conjugation: Via mating with another cell

Produce all or most of their own organic compounds

Use light as energy source for synthesis of organic compds frm CO₂ or H₂S.

Use energy obtained from chemical modification of inorganic compds to synthesize organic compds

Organisms that require at least one organic compd and often more

Able to use light energy to make ATP but they must take in organic compds from the envirnmt

Must obtain organic molecules for both energy and carbon source.

Require oxygen

can use oxygen or not

cannot tolerate oxygen

Do not use oxygen but are not poisoned by it

• Producers synthesize organic compds used by other organisms as food
• Decomposers break down dead organisms to release minerals for reuse
• Methanogens-makes methane
• Methanotrophs- consume methane

An organism that lives in close association with one or more other organisms

One partner benefits at the expense of the other

Association beneficial to both partners

Some bacteria live together and supply each other with essential nutrients

Larger community of nutrient exchangers.

IE: Marine worm with no mouth, gut, or anus depends on bacteria inside it for food and waste recycyling

• Bacteria induces normal development in Ulva
• Bioluminescent bacteria in squid and other animals