Ch 1 - Invisible World

what are the three notions of microbes? (1/3)

• Otiz the Iceman

  • Borrelia burgdorferi (Lyme disease)

what are the three notions of microbes? (2/3)

• The Bible

  • isolating M. leprae

what are the three notions of microbes? (3/3)

• ancient greeks & romans

  • greeks - mal’aria/miasma

  • romans - aquaducts/cloaca maxima

what are microorganisms or microbes?

• very small organisms

  • many are too small to see w the naked eye

    • parasites & fungi are an exception

what did our ancestors discover?

• link to “germs“ & health

• took advantage of fermentation to to preserve food & enhance taste

what are some early notions of hygiene?

• greatest sewer or the cloaca maxima

  • carried waste away and into the river Tiber (Rome)

• roman latrines

  • emptied into the cloaca maxima

who is Hippocrates & what did he do?

• “father of Western medicine“

  • proposed illnesses come from natural causes instead of supernatural forces

  • often credited to have written the Hippocratic Corpus & Hippocratic Oath

who is Thucydides? & what did he do?

• father of scientific history

  • advocated for evidence-based analysis of cause-and-effect reasoning

  • observed that patients prev sick of the Athenian plague didn’t get re-infected

    • shows early understanding of immunity

who is Antonie van Leeuwenhoek & what did he do?

• 1st to develop a lens powerful enough to view microbes

  • able to observe single-celled organisms in a drop of rain water - “animalcules“

    • looked at bacteria & protists

who is Louis Pasteur and Robert Koch?

active in advancing our understanding of the unseen world of microbes

what did Louis Pasteur do? (1/2)

• showed individual microbial strains had unique properties

• showed that fermentation is caused by microorganisms

what did Louis Pasteur do? (2/2)

• invented pasteurization

  • process used to kill microorganisms responsible for spoilage

• developed vaccines for treatment of diseases (like rabies) in animals & humans

what did Robert Koch do?

• 1st to show connection between a single, isolated microbe & a known human disease

• discovered bacteria causing anthrax (Bacillus anthracis), cholera (Vibrio cholera), and tuberculosis (Mycobacterium tuberculosis).

who is Edward Jenner & what did he do?

• created world’s 1st smallpox vaccine

• pioneered concept of vaccination

• laid groundwork for modern immunology

what are microscopes?

produce magnified images of microorganisms, human cells, tissues, etc. that are too small to observe w naked eye

what are stains & dyes?

• used to add color to microbes so they can be seen better

  • some can be used on living microbes

  • some only work on certain types of microbes

what are growth media?

• used to grow microorganisms in a lab setting

• some are liquid, gel-like, or more solid

  • provides nutrients (water, various salts, source of carbon, sources of nitrogen & amino acids)

what is a petri dish?

• flat-lidded dish typically 10-11 cm in diameter & 1-1.5 cm high

• made out of plastic or glass

• used to hold growth media

what are test tubes?

• cylindrical plastic or glass tubes w rounded bottoms & open tops

• used to grow microbes in broth or semisolid or solid growth media

what is a bunsen burner?

• metal apparatus that creates a flame that can be used to sterilize pieces of equipment

• rubber tube carries gas (fuel) to burner

• being phased out in favor of microincinerators

what are microincinerators?

serve similar purpose to bunsen burner without risk of open flame

what is an inoculation loop?

• handheld tool that ends in small wire loop

• used to streak microorganisms on agar in a Petri dish or transfer them from one test tube to another

• must be sterilized before usage

what is taxonomy?

classification, description, identification, & naming of living organisms

who is Carolus Linnaeus?

• published systema Naturae

  • 11 pg booklet where he proposed Linnaean taxonomy

    • system of categorizing & naming organisms using a standard format

    • helps scientists use consistent terminology

• divided natural works into 3 kingdoms: animal, plant, & mineral

what is phylogeny?

• evolutionary history & development of a group of organisms

  • lineage tree; explanation of how sequences evolved

what are the three domains in phylogenies?

• bacteria: single-celled prokaryotes

• archaea: single-celled prokaryotes

• eukarya

  • have distinct nucleus

  • includes single-celled & multicellular organisms

what role do genetics play in modern taxonomy?

• allow for standardized way to compare all living organisms w/o relying on observable characteristics that can often be subjective

• relies heavily on comparing nucleic acids (DNA or RNA) or proteins from diff organisms

  • more similar = more closely related

who is Carl Woese & what did he do?

discovered what appeared what appeared to be “living record“ of evolution of organisms

what did Carl Woese & George Fox do?

• created a genetics-based tree of life based on similarities & diffs they observed in gene sequence coding for small RNA of diff organisms

  • discovered archaeabateria

    • suggests archaea, bacteria, & eukaryotes all evolved from common ancestral cell type

what is binomial nomenclature?

• two-word naming system for identifying organisms by genus & specific epithet

  • Homo - genus; sapiens - epithet

  • binomial nomenclature - Homo sapiens

what is Bergey’s manuals?

• standard references for identifying & classifying diff prokaryotes

  • based on nonvisual characteristics to ID them

what are pathogens?

bacteria that causes diseases in humans & other animals

what are bacteria?

• found in nearly every habitat on earth

• prokaryotic bc their DNA isn’t housed within a true nucleus

• often described in terms of their general shape

what are archaea?

unicellular prokaryotic organisms

what are protists?

• informal grouping of eukaryotes that aren’t plants, animals, or fungi

  • some algae are protists & others are bacteria

what are fungi?

• are also eukaryotes

• some multicellular fungi resemble plants

• aren’t photosynthetic

what are fungi - yeast?

• more than 1000 known species

• found in diff environments

• have beneficial uses, such as causing bread to rise & beverages to ferment

  • can also cause food to spoil or cause diseases

what are fungi - mold? (1/2)

• multicellular organisms

• made up of long filaments that form visible colonies

what are fungi - mold? (2/2)

• play critical role in decomposition of dead plants & animals

• can cause allergies or produce disease-causing metabolites

• used to make pharmaceuticals, including penicillin & cyclosporine

what are helminths?

• multicellular parasitic worms

• aren’t technically microorganisms & most are large enough to see w/o microscope

• diseases are caused by microscopic eggs & larvae

what are viruses?

• acellular microorganisms

• not composed of cells; made of proteins & DNA or RNA

• are inert outside of host organism

  • able to co-opt host’s cellular mechanisms to multiply and spread

what is microbiology?

broad term that encompasses study of all diff types of microorganisms

what is bacteriology?

study of bacteria

what is mycology?

study of fungi

what is Parasitology?

study of helminths & other parasites

what is Immunology?

study of immune system

what is Virology?

study of viruses