Bacteria

Bacteria differ from Eukaryotes No nucleus or membrane bound organelles 10 times smaller Unicellular, activities not specialized Single chromosome Reproduce by binary fission Simple flagella that spins, pili for adherence Many metabolic abilities, perform any aerobic and anaerobic processes

Structure of bacteria 3 basic shapes 1. Bacillus – rod shaped cell 2. Coccus – round shaped cell 3. Spirillum – spiral cell

Structure of bacteria Cell membrane and cell wall Capsule – gel like layer outside cell wall Endospores – in harsh conditions, form around chromosomes and cytoplasm. Pili – adhere to surfaces Conjugation – exchange of genetic material

Bacteria obtain energy many ways Photosynthetic bacteria – many bacteria carry out photosynthesis ex. Cyanonbacteria Chemoautotrophic bacteria – obtain energy by removing electrons from inorganic (NH3) or organic molecules (methane). Play important role in nitrogen cycle. Heterotrophic bacteria – feed on organic material formed by other organisms, decomposers

Gram staining (Lab) Gram + - bacteria with a thick layer of peptidoglycan, stain violet Gram - = bacteria with a thin layer of peptidoglycan, stain pink Important because they differ in susceptibility to antibiotics Knowing whether a bacteria is gram + or gram – will help a doctor choose the most effective antibiotic.

Bacteria cause disease Metabolize host – secrete enzymes to break down organic structures TB – bacteria grow on human tissue in lungs Acne – metabolize oil produced in glands, plugs the pores, forming pimples

Bacteria cause disease Toxins – bacteria secrete chemicals (toxins) that are poisonous to eukaryotic cells Food poison – bacteria grow and produce toxins in food. This causes illness in humans that eat the contaminated food Botulism – poorly canned food – not heated enough to kill endospore E. coli poisoning – raw/inappropriately cooked ground beef

Fighting Bacteria Hot soapy water antibacterial products Antibiotics- natural or synthetic

Importance of bacteria Foods are processed by bacteria Pickles, buttermilk, cheese, sauerkraut, olives, vinegar Industrial uses Acetone, butanol (bases for other useful chemicals) Genetic engineering Mining – concentrate desired elements from low grade ore Environmental - help clean up environmental disasters by metabolizing organic chemicals, oil and chemical spills