Prokaryotes aka Bacteria

Bacteria in everyday life Decomposers Nitrogen fixation Blue-Green Algae Genetic Engineering Digestion/vitamin synthesis Food production: yogurt, pickles, soy sauce, wine, vinegar, sauerkraut Diseases: Syphilis, Tetanus, Tuberculosis, Cholera, Leprosy, Botulism

Decomposers

Nitrogen Fixation

Blue-Green Bacteria

Genetic Engineering

Digestion/Vitamin synthesis

Food Production

Bacterial Diseases Pneumonia Black Plague Tuberculosis Leprosy Botulism Diphtheria Anthrax Endotoxins: contained inside the bacteria and released when they die, e.g. Salmonella. Cause fever, vomiting and diarrhea Exotoxins: release toxins which travel through body. e.g. Tetanus, botulism, no fever

Characteristics of Bacteria Single-celled Prokaryotes – DNA is not surrounded by a membrane, i.e. no nucleus Organelles are not surrounded by membranes Bacterial DNA is a single chromosome in the shape of a ring called a plasmid Reproduce asexually by binary fission

Bacterial Structure

Comparison of Prokaryotic vs Eukaryotic Cells

Cell Shapes and Colonies Bacteria can be classified by shape and colony

Cocci Round bacteria

Bacilli Rod-shaped

Spirilla Spiral-shaped

Bacterial Colonies Diplo – pairs Staphylo – grape-like clusters Strepto – long chains

Nutrition Heterotrophs – obtain energy by breaking down organic molecules from their environment (decomposers) Autotrophs – produce own organic compounds Photoautotrophs – use sunlight (cyanobacteria) Chemoautotrophs – use chemical reactions

Respiration Aerobic - require oxygen for cellular respiration obligate aerobes – require oxygen for survival Anaerobic – do not require oxygen for cellular respiration Obligate anaerobes – killed in the presence of oxygen, e.g. clostridium botulinum

Reproduction Bacteria reproduce via binary fission (dividing in two)

Bacterial Conjugation Bacteria can exchange genetic information through conjugation

Archaebacteria vs Eubacteria oldest group of organisms Usually found in harsh/extreme environments Cell wall and membrane chemically different from eubacteria Three main types: Methanogens: produce methane (swamp gas) Halophiles: salt-loving Thermophiles: heat-loving – hot, acidic environments

Archaebacteria vs Eubacteria Extremely diverse Spirochaetes Chlamydias Gram-positive bacteria Cyanobacteria Proteobacteria