4: Archaea & Bacteria (Prokaryotes)

• Coarse Groups


  Methanogens, halophiles, and thermophiles.
• Achromatism Oxaliferum


  A prokaryote up to 100μg in size.
• Use of gram-positve and negative


  A quick technique to determine if bacteria are toxic or pathogenic.
• Plasmids


  Extra circular DNA with antibiotic resistance.

  
• Cytoplasm

  80% water and 20% salts and proteins. DNA in a nucleotide, plasmids for antibiotic resistance, no membrane-bound organelles.

  
• Fimbriae / Pili


  Short protein appendages, greater than flagella.

  
• Lophotrichous

  Tuft at one end.

  
• Monotricious


  One flagellum.

  
• Atrichous


  No flagella.

  
• Motility


  Movement
• Cell Membrane

  Bilayer phospholipid, selectively permeable, encloses the cytoplasm.

  
• Peptidoglycan Polymer

  Polypeptides and sugars.
• Cell Wall

  Determines shape, prevents osmotic rupture, unique to prokaryotes.

  
• Glycolax


  Polysaccharide or protein on the external surface.
• Woese et al. 1990


  Scientist known for determining the relationships of organisms in the three main domains of life

  
• Thermophiles


  Archaea tolerant to high temperatures, found in hot springs
• Halophiles


  Archaea tolerant to high salt levels, responsible for pink color in some environments

  
• Methanogens


  Archaea producing methane gases, often found in human gut

  
• Gram-negative


  Bacteria with thinner peptidoglycan, stained pink, and an outer toxic membrane.

  
• Gram-positive

  Bacteria with thick peptidoglycan cell walls, stained purple. Violet stain trapped in cytoplasm.

  
• Flagella


  Prokaryotic motility appendages, basis for classification

  
• Fimbriae


  Short protein appendages adhering prokaryotes to surfaces
• Vibrio cholera

  Vibrio prokaryote causing cholera

  
• Escherichia coli


  Bacillus prokaryote, 0.1% of gut flora, causes food poisoning

  
• Staphylococcus aureus

  Coccus prokaryote causing minor skin infections to pneumonia and meningitis

  
• Vibrio / Spirillum / Spriochaete

  Spiral-shaped prokaryote

  
• Bacillus


  Rod-shaped prokaryote

  
• Coccus


  Spherical prokaryote shape

  
• Achromatium oxaliferum


  A type of prokaryote up to 100 microns in size
• Prokaryote Size

  Average size 0.5 - 5 μm, some can be as large as almost 1mm. 12μg2 surface area. 4μg3 volume. 3:1 surface area to volume.
• Domain


  The highest taxonomic rank of organisms
• Ribosomal RNA


  RNA used for determining relationships in the three main domains of life
• Eukarya


  Domain including humans, animals, plants, fungi, and multicellular algae
• Bacteria

  Prokaryotes, most life on Earth is microbial

  
• Archaea


  Prokaryotes in the 3 Domain system, often extremophiles

  
• Prokaryotes


  Single-celled organisms without a nucleus. Split into two domains: Archaea and bacteria.

  
• Gram-positive bacterial cell walls have thicker layers of peptidoglycan compared to Gram-negative cells.
• Bacterial cell walls are made up of peptidoglycan, which is composed of sugars and amino acids.
• Peptidoglycan provides structural support to the cell wall and helps maintain its shape.
• Ubiquitous Nature: present everywhere and widespread, large domain of single-celled prokaryotic organisms