microbiology

they are single-celled, prokaryotic, and members of two domains: eubacteria and archaea most bacteria is decomposers

prokaryotes- bacteria, protozoans, fungi, plants - ribosomes (but smaller) - cell wall eukaryotes- animal - nucleus - organelles - ribosomes - cell walls (some)

anaerobes- without oxygen facultative- with or without oxygen microaerophiles - reduce oxygen levels

thermophiles- elevated temperatures mesophiles- moderate temp psychrophiles- cold temp

halophiles- grow at elevated salt concentration

photosynthetic and produce O2

cocci- round bacilli- rod-shaped spirals- including vibrios which are half spiral and spirochetes which are tightly wounded spirals

rigid layer outside of their plasma membrane - cell wall made up of peptide cross-bridges called peptidoglycan (two forms) - gram-positive- are thick with many peptidoglycan layers - gram-negative- have a small amount of peptidoglycan with an outer membrane of lipopolysaccharide ) LPS_

for movement

hair like structures for attachment to surfaces

pilus for exchange of DNA

sugar containing the outer layer, which protects bacteria or helps attach it to surfaces. example-capsule on some bacteria protect against phagocytosis

circular and free-floating within a cell and no membrane-bounded organelles

some have circular piece of DNA that replicates independently of the chromosomes and may carry genes (R factor) for antibiotics resistance plasmids can move between bacteria

(Bacillus and Clostridium) make very tough survival structure

slightly smaller and function slightly differently

the most widely used. It involves a decolorization step with alcohol that removes the color from cells with the thinner gram-negative cell wall. the gram-positive cells hold the purple primary stain and gram-negative cells are counterstained pink after being decolorized

enteric or coliform bacteria, includes E. coli, salmonella, and shigella, cause a variety of infections in the GI tract, also serves as an indicator of pollution since they are only found in the gut and feces

staphylococcus and streptococcus cause a wide variety of infections in the skin, respiratory tract, and elsewhere. a deadly disease caused by stroptococcus pneumoniae is pneumococcal pneumonia

a spore-forming anaerobic gram-positive rod is clostridium the cause of dangerous diseases including tetanus, botulism, clostridum difficle infection and gas gangrene. Mycobacterium has an outer layer of wax/lipid (referred to as acid fast because of how they stain and causes the lung diseases tuberculosis, characterized by coughing

causes pertussis, commonly known as whooping cough, where a toxin damages the airways

two spirochetes are Borrelia, the cause is Lyme disease-transmitted by a tick and Treponema, the cause of the STD syphilis

eukaryotic, single-celled, they move by a variety of means including flagella, cilia, or amoeboid motion

very complex, many can make a tough survival stage called cyst, which is often the stage that transmits disease (such as giardia, cryptosporidium, or Entamoeba) remainder of the time they are in a form called trophozoite