More on Monerans

The THREE basic bacterial shapes Rod: bacilli Sphere: cocci (form long chains or clumps, Ex. Streptococcus) Spiral: Spirilla

Structural Differences Gram positive Gram negative Purple when treated with dye; carbohydrate & protein molecules outside cell membrane (one thick layer) Red when treated with dye; second outer layer of lipid (fat) & carbohydrate

Bacterial Movement Flagella “Spiral” or rotate forward Slimy secretions allow gliding over a surface

Bacterial Respiration Obligate aerobes Obligate anaerobes Require a constant supply of oxygen to survive Oxygen needed to break down food molecules Do not require oxygen to survive

An obligate anaerobe example… Clostridium botulinum Found in soil When oxygen absent, will grow, reproduce & produce TOXINS (poisons) Can cause paralysis or death in humans if ingested

Facultative Anaerobe: Do not require oxygen to survive BUT are not poisoned by its presence

Obtaining Energy Phototrophic autotrophs Chemotrophic autotrophs Photosynthesize (can make own food… similar to plants) Example: cyanobacteria, photosynthetic eubacteria Obtain energy from inorganic molecules (nitrites, sulfur, iron) Example: nitrosomonas

* All other organisms fall into the Domain Eukarya (Eukaryotes) Bacterial Groups Bacteria- diverse group Archaea Extreme thermophiles: live in hot environments (thermal vents in ocean, volcanic springs) Extreme halophiles: live in very salty environments (Dead Sea, salt flats) Methanogens: anaerobes (poisoned by oxygen)- use CO2 to oxidize H2 & release methane in the process * All other organisms fall into the Domain Eukarya (Eukaryotes)

Take in organic molecules & break them down for use in cell Chemotrophic heterotrophs Phototrophic heterotrophs Take in organic molecules & break them down for use in cell Example: salmonella Photosynthetic BUT they also need organic compounds for certain nutrients