bacteria. classification unicellular prokaryotes 2 domains achaea –kingdom archaebacteria...
TRANSCRIPT
Classificationunicellular prokaryotes
2 Domains• Achaea
– Kingdom Archaebacteria (ancient)– found in marshes, swamps, hot sulfur
springs, Great Salt Lake, deep ocean vents • Bacteria
– Kingdom Eubacteria (true)– found in almost any habitat
Bacteria
Classification
Kingdom Archaebacteria
• cell walls without peptidoglycan (carbohydrate)
• autotrophic or heterotrophic
• live anaerobically
• live in harsh environments (great salt lakes, hot springs)
• ex: Methanogens (in digestive tract of animals), Halophiles (salt-loving)
Bacteria
Classification
Kingdom Archaebacteria
• live in harsh environments (great salt lakes, hot springs)
Bacteria
Classification
Kingdom Eubacteria
• cell wall contains peptidoglycan (carbohydrate)
• autotrophic or heterotrophic
• free living (ponds, streams, on dead organisms) or deadly parasites
• ex: streptococcus, Escherichia coli, anabaena
Bacteria
Cell structure
• cell wall
• nucleic acid
• capsule
• flagella
• pili
• ribosomes
• plasmid
Bacteria
Cell structure
• endospore– tough protein coat formed inside cell; used to
survive harsh conditions
Bacteria
Classifying Bacteria
bacteria are classified according to:
• shape
• arrangement
• staining properties
Bacteria
Classifying Bacteria
shape
• spherical– coccus/cocci
• rod– bacillus/bacilli
• spiral– spirillum/spirilli
Bacteria
Classifying Bacteria
staining properties
• gram stain negative
– thin layer of peptidoglycan
– stains pink
• gram stain positive
– thick layer of peptidoglycan
– stains purple
Bacteria
Life processes
nutrition
• heterotrophs
– parasitic
• ex: staphylococcus aureus
– saprophytic
Bacteria
Life processes
nutrition
• chemosynthetic autotrophs
– energy from chemicals
– ex: Nitrobacteria
Bacteria
Life processes
respiration• obligate aerobes
– require O2 to live– ex: tuberculosis
• obligate anaerobes– can not live in presence of O2
– ex: botulism • facultative anaerobes
– lives with or without O2
– ex: E. Coli
Bacteria
Life processes
reproduction
• conjugation– transfer of genetic material to an acceptor bacterium– sexual reproduction
Bacteria
Life processesreproduction• spores
– buds form and produce new cells– spores can survive a long time before
“hatching”
Anthrax spores
Bacteria
Advantages of bacteria• human intestine• food production-
– milk, buttermilk, yogurt, sour cream, cheese• ecology
– decomposers– nitrogen fixation
• producers
Bacteria