Microbiology
study of organisms to small to be seen with out magnification.
Microorganisms include:
-Bacteria
-Viruses
-Fungi
-Protozoa
-Helminths (worms)
-Algae
Two Cell Lines
-Prokaryote
-Eukaryote
-Prokaryote
-microscopic, unicellular oranisms, lack nuclei and membrane-bound organelles.
-Eukaryote
-unicellular (microscopic) and multicellular, nucleus and membrane-bound organelles. "True Nucleus
-Viruses
-Acellular, parasitic particles composed of a nucleic acid and protein. Viruses are nonliving.
Lifestyles of Microorganisms
-majority live a free existence, are relatively harmless and often beneficial.
-Many microorganisms have close associations with othe organisms.
-Parasites
-Hosts
Spontaneous Generation
Early belief that some forms of life could arise from vital forces present in nonliving or decomposing matter (flies from manure, etc.)
Antoni van Leeuwenhoek (1632-1723)
-Dutch linen merchant.
-First to observe living microbes.
-Single-lens magnified up to 300X.
Scientific Method
Experimental system that answers questions objectively (free from bias) arose in the 1600s.
The Development of Medical Microbiology
-Early experiments led to the realization that microbes are everywhere
-This discovery led to immediate applications in medicine
Germ theory of disease: resulted in the use of sterile, aseptic, and pure culture techniques
Germ theory of disease:
resulted in the use of sterile, aseptic, and pure culture techniques.
Discovery of Spores and Sterilization
-John Tyndall and Ferdinand Cohn each demonstrated the presence of heat resistant forms of some microbes.
-Cohn determined these forms to be heat-resistant bacterial endospores.
Sterility
-requires the elimination of all life forms including endospores and viruses.
Development of Aseptic Techniques
-The human body is a source of infection.
-Dr. Oliver Wendell Holmes - observed that mothers of home births had fewer infections than those who gave birth in hospitals
-Dr. Ignaz Semmelweis - correlated infections with physicians coming directly from auto
Joseph Lister
- introduced aseptic techniques reducing microbes in medical settings and preventing wound infections.
-Involved disinfection of hands using chemicals prior to surgery
-Use of heat for sterilization
Pathogens and Germ Theory of
Disease
-Many diseases are caused by the growth of microbes in the body and not by sins, bad character, or poverty, etc.
-Two major contributors:
-Louis Pasteur
-Robert Koch
Louis Pasteur (1822-1895)
-Showed microbes caused fermentation and spoilage
-Disproved spontaneous generation of microorganisms
-Developed pasteurization
-Demonstrated what is now known as Germ Theory of Disease
Robert Koch (1843-1910)
-Established Koch's postulates - a sequence of experimental steps that verified the germ theory
-Identified cause of anthrax, TB, and cholera
-Developed pure culture methods
Taxonomy
-organizing, classifying, and naming living things.
-Formal system originated by Carl von Linn� .
Primary Concerns of Taxonomy:
-Classification - orderly arrangement of organisms into groups
-Nomenclature - assigning names
-Identification - determining and recording traits of organisms for placement into taxonomic schemes
Levels of Classification
-Domain - Archaea, Bacteria, & Eukarya [ DID ]
-Kingdom [ KENTUCKY ]
-Phylum [ PLAY ]
-Class [ CONNETICUT ]
-Order [ OR ]
-Family [ FLORIDA ]
-Genus [ GAME ]
-Species [ SATURDAY ]
3 Domains of classification
-Bacteria - true bacteria
-Archaea - odd bacteria that live in extreme environments, high salt, heat, etc.
-Eukarya - have a nucleus and organelles
Assigning Specific Names
-Binomial (scientific) nomenclature
-Gives each microbe 2 names:
-Genus - capitalized
-species - lowercase
-Both italicized or underlined
-Staphylococcus aureus (S. aureus)
-Inspiration for names is extremely varied and often imaginative
Which of the following is not considered a microorganism?
-alga -bacterium -protozoan -mushroom
-mushroom
epidemiology
-An area of microbiology that is concerned with the occurrence of disease in human population.
recombinant DNA
Process involves the deliberate alteration of an organism's genetic material.
The prominent difference between prokaryotic and eukaryotic cells....
-presence of a nucleus in eukaryotes
Which of the following parts was absent from Leeuwenhoeks's microscopes?
-focusing screw -lens -specimen older -condenser
-condenser
Abiogenesis refers to....
-spontaneous generation of organisims from nonliving matter.
A hypothesis can be defined as....
-a scientific explanation that is subject to testing.
Which early microbiologist was most responsible for finally laying the theory of spontaneous generation to rest?
- Joseph Lister -Robert Koch -Francesco Redi -Louis Pasteur
-Louis Pasteur
Whaen a hypothesis has been throughly supported by long-term study and data, it is considered...
-a theory
what is the correct order of the taxonomic categories, going from the most specific to the most general?
-species, genus, family, order, phylum, kingdom, domain.
By definition, organisms in the same____are more closely related than are those in the same____.
-class
-phylum
Which of the following are prokaryotic?
-bacteria -archaea -protists -both bacteria and archaea
-both bacteria and archaea
Order the following items by size, using numbers 1=smallest and 8=largest.
__Aids virus __worm
__amoeba __coccus-shaped bacterium
__rickettsia __white blood cell
__protein __atom
3) Aids virus 8) worm
7) amoeba 5) coccus-shaped bacterium
4) rickettsia 6) white blood cell
2) protein 1) atom
Which of the following is not an emerging infectious disease?
-avian influenza -SARS -common cold -AIDS
-common cold
How would you classify a virus?
-prokaryotic -eukaryotic -or neither prokaryotic or eukaryotic
Explain answer.
-neither prokaryotic or eukaryotic
because it is not cellular and not alive.