Chapter 1: Introduction to Microbiology Flashcards
Microbiology
the stud of microorganisms or microbes; which are often invisible to the naked eye; at least half of earths life is microbial; inhabit every region
Microbe encompasses…
cellular, living microorganisms (bacteria, archaea, fungi, protists, and helminths); nonliving/noncellular entities (viruses and prions (infectious proteins)); and microorganisms that are not microscopic (some fungi, helminths, and protists)
Bacteria
prokaryotic; unicellular, pathogenic and nonpathogenic
Archaea
prokaryotic; unicellular; nonpathogenic; most live in extreme environments
Protists
eukaryotic; unicellular and multicellular; pathogenic and non pathogenic; unicellular- amoebae; multicellular- algae
Fungi
Unicellular and multicellular; pathogenic and nonpathogenic
(unicellular example: yeast; multicellular example: mushrooms
Helminths
eukaryotic; Multicellular;* parasitic roundworms and flatworms
Viruses
not cells; nonliving ; Infect animal, plant, or bacterial cells; can have a D NA or RNA
genome; they are considered non-living because they can not live outside of a host and do not create their own energy (metabolism)
Prions
not cells; nonliving; infectious proteins; Not discovered until the 1980s; transmitted by transplant or
ingestion; some prion diseases are inherited
Prokaryotic Cells
evolved about 3.5 billion years ago; earliest life forms; include unicelluar bacteria and archaea; does not contain membrane bound organelles and a nucleus
Eukaryotic Cells
all multicellular organisms and a number of unicellular microorganisms (amebae, yeast); contain membrane bound organelles and a nucleus; endosymbiotic theory
Pathogens
microbes that cause disease; about 1400 are known to infect humans; < 1% of all microbes are pathogenic
Opportunistic Pathogens
cause disease only in a weakened host; like already having a disease and the opportunistic pathogen taking advantage of that
Golden Age of Microbiology
1850-1920; innovation of microscops; observations; new techniques to isolate and grow microbes
Edward Jenner
successfully vaccinates against small pox
Florence Nightingale
establishes formal aseptic practices in nursing
Joseph Lister
think listerine; publishes aseptic surgery techniques
Robert Koch
first to prove microbes cause disease
Julius Petri
makes first petri dish
Alexander Fleming
discovers penicillin
Robert Hooke
first to publish descriptions of cells (cork)
Antonie Van Leeuwenhoek
refined earlier versions of the microscope and developed a better lens to focus on specimen; first to see bacteria
Spontaneous Generation
abiogenesis; life comes from nonliving items; like how they believed maggots just spontaneously came to be on meat
Biogenesis
life emerges from existing life (reproduction); the maggots were not sponateous and instead came from the flies that laid their eggs
Francesco Redi
tested spontaneous generation by leaving meat in an uncovered jar which resulted in maggots and then a meat in a sealed jar which resulted in no maggots on meat
Louis Pasteur
showed biogenesis is responsible for the propagation of life; pasteurization killed off yeast and prevented stored wine from turning sour (vinegar); developed first vaccine against anthrax and rabies; developed germ theory
Germ Theory of Disease
states that microbes cause infectious diseases; specifically infectious because some disease can be genetic, autoimmune, or cancer none of which are infectious
Endosymbiotic Theory
eukaryotic cells evolved from prokaryotic cells in a sequential way
What famous experiment did Pastueur do to disprove spontaneous generation?
swan necked flask experiment
How did the S-Neck experiment leave no room for skeptics to say that it still could have been spontaneous generation?
the flask had an opening that allowed air into the container; this meant that “life force” was not blocked
Why did the shape of the s-necked flask matter so much?
it did not allow particles/microbes to enter to the broth; gravity, water, and air (or currents) are the only thing that can move microbes; the s-neck did not allow the microbes to move because they were stuck in the bottom part; there was no gravity to push them up, no air current or liquid
How do microbes move?
either passively (such as gravity) or actively (with a flagella, cilia, or amoeba motion); this means that they require a aqueous environemnt to do so in
Scenario 1 of Swan Neck Experiment
broth is heated and cooled in flask; nothing is done; microbes are trapped in the neck and the broth remains pure
Secanrio 2 of Swan Neck Experiment
broth heated and cooled; microbes are trapped in neck; but the flask is tilted to the liquid goes up the neck which allows the microbes to get in the liquid and the broth is contaminated
Scenario 3 of Swan Neck Experiment
broth heated and cooled; microbes stuck in flask; break the neck of the flask (take out the S part) and airborn microes enter thorugh gravity and the broth is contaminated
Turbid
growth of microbes in a broth; cloudy broth
How do bacteria reproduce?
binary fission
What did the swan neck lead to?
creation of the petri dish; it is the same concept; the cover of the petri dish is larger and when it sits on top creates the “swan neck” shape
Robert Koch
interested in what specific microbe causes a specific disease; developed staining techniques and media for the isolation and cultivation of bacteria; worked with anthrax and found it was caused by the bacteria bacillus anthracis; developed a technique to determine the specific etiological agent of an infectious disease
Koch’s Postulates of Disease
1) same organisms must be present in every case of the disease; 2) organism must be isolated from the diases host and grown as a pure culture (taking the microbe out of the host and cultivating it); 3) isolated organism should cause same disease when iinoculated into a susceptible host (the microbe is given to a healthy host and should present the same symptoms as the infected host); 4) organism must be re-isolated from the inoculated, diseased animal (must be able to pull that same microbe out and determine that it was what caused the disease)
Ignaz Semmelweis
developed first aseptic techniques in the hospital setting; recommended handwashing to decrease mortality rates from childbed fever; father of handwashing
Joseph Lister
investigated processes for aseptic surgery; proved sterilizing instruments and sanitizing wounds with carbolic acid prevented pus formation
Florence Nightingale
established aseptic techniques in nursing; founder of modern nursing
What do aseptic processes prevent?
healthcare-acquired infections (HAIs) aka nosocomial infections and limited the spread of disease; types include hand washing, wearing gloves, sterilizing instruments, and decontaminating surfaces
Scientific Method
starts with a question that can be investigated; a hypothesis (proposed answer) is proposed; researches collect and analyze observations (data) and use them to formulate a conclusion; conclusion states whether the data supports or contradicts the hypothesis
Observation
any data collected using our senses or instrumentation
Conclusion
interprets observations; take a collection of observations to draw accurate conclusions
Law
a precise statement (or mathematical formula) that predicts a specific occurrence; predicts what happens
Theory
a hypothesis that has been proven through many studies with consistent, supporting conclusions; explain why and how something occurs