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Prokaryotes: Kingdoms Archaebacteria and Eubacteria. Chapter 18. Daily Objective. Investigate Prokaryotes and their two Domains: Domain Archaea and Domain Bacteria. Bacteria are the most numerous organisms on Earth Earliest life forms Contain no nucleus or membrane bound organelles
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Prokaryotes: Kingdoms Archaebacteria and Eubacteria Chapter 18
Daily Objective • Investigate Prokaryotes and their two Domains: Domain Archaea and Domain Bacteria
Bacteria are the most numerous organisms on Earth • Earliest life forms • Contain no nucleus or membrane bound organelles • Most are unicellular FASTFACTS
Prokaryotes are divided into 2 domains. • Domain Archaea and Domain Bacteria • Review Domain Archaea live in extreme enviornments . They have been found to have similarites with eukaryotic cells. i.e. the ribosomal proteins Domain Bacteria live in nearly every environment on Earth. Their cell walls contain peptidoglycan.
Daily Objective • Review Characteristics of Prokaryotes
Domain Archaebacteria • “ancient bacteria” • Cell walls without peptidoglycan • Subdivided into 3 groups based on their habitat– methanogens, thermoacidophiles, & extreme halophiles
Domain Bacteria • “true bacteria” • Most bacteria in this kingdom • Come in 3 basic shapes cocci (spheres), bacilli (rod-shaped), spirilla (corkscrew shape) • Most are heterotrophic • Can be aerobic, or anerobic
Gram Staining • Developed in 1884 by microbiologist Hans Gram • Bacteria are stained purple with dye and iodine, rinsed with alcohol to decolorize, then restained with dye. • Bacterial cell walls either stain purple or reddish-pink
Gram +/- Gram (+) Bacteria Gram (-) Bacteria Stain reddish-pink Thin layer of peptidoglycan Antibiotic resistant Examples; Rhizobacteria, Rickettsia (Lyme disease) • Stain purple • Thick layer of peptidoglycan (protein sugar complex in cell walls) • Examples: streptoccous, staphylocci • Can be treated with penicillin (antibiotics)
Prokaryote Characteristics • Bacteria can be identified by their shape, cell wall, and movement. • Shape
Prokaryote Characteristics- cell walls All bacterial cells have peptidoglycan (sugar and protein) in their cell walls -can identify bacteria by gram staining. • Bacteria with a large amount of peptidoglycan appear dark purple (gram +) • Bacteria with a lipid layer has less peptidoglycan, and will stain reddish pink (gram-)
Reproduction of Prokaryotes • Most bacteria reproduce asexually by binary fission- chromosome replicates then the cell divides • Bacteria can sexually reproduce by conjugation- two bacteria from a conjugation bridge or tube between them.
Metabolism of Prokaryotes • Prokaryotes can obtain their energy in multiple ways