Microbes
Also called microorganisms; are minute living things that individually are usually too small to be seen with the unaided eye. The group includes bacteria, fungi (yeasts and molds), protozoa, microscopic algae, and viruses.
Pathogenic
Disease producing
Scientific Nomenclature
Established in 1735 by Carolus Linnaeus; assigns each organism 2 names -- the GENUS (plura: genera) is the first name and is always capitalized; the specific epithet (species name) follows and is not capitalized. Both names are underlined or italicized.
S
Bacteria
Relatively simple, single-celled (unicellular) organisms. Because their genetic material is not enclosed in a special nuclear membrane, bacterial cells are called prokaryotes (prenucleus). Prokaryotes include both the bacteria and the archaea. Shapes incl
Archaea
Like bacteria, archaea consist of prokaryotic cells, but if they have cell walls, the walls lack peptidoglycan; they are often found in extreme environments and are divided into 3 groups: methanogens, extreme halophiles, and extreme thermophiles.
Methanogens, Halophiles, and Thermophiles
Methanogens produce methane as a waste product from respiration. The extreme halophiles live in extremely salty environments; extreme thermophiles
Fungi
Eukaryotes, organisms whose cells have a distinct nucleus containing the cell's genetic material (DNA), surrounded by a special envelope called the nuclear membrane.
Protozoa
are unicellular, eukaryotic microbes. Protozoa move by pseudopods, flagella, or cilia.
Algae
are photosynthetic eukaryotes with a wide variety of shapes and both sexual and asexual reproductive forms. Algae of interest to microbiologists are usually unicellular.
Viruses
are so small that most can be seen only with an electron microscope, and they are acellular. Structurally very simple, a virus particle contains a core made of only one type of nucleic acid, either DNA or RNA.
List the 3 domains
1) Bacteria
2) Fungi
3) Plants
*In 1978, Carl Woese devised a system of classification based on the cellular organization of organisms. It groups all organisms in three domains above.
1) Bacteria
cells walls contain a protein-carbohydrate complex called peptidoglycan
2) Fungi
Unicellular yeasts, multicellular molds, and mushrooms
3) Eukarya
Includes the following:
* Protists (slime molds, protozoa, and algae)
* Fungi (unicellular yeasts, multicellular molds, and mushrooms)
* Plants (includes mosses, ferns, conifers, and flowering plants)
* Animals (includes sponges, worms, insects, and verte
Robert Hooke
In 1665, after observing a thin slice of cork, an Englishman, Robert Hooke, reported that life's smallest structural units were "little boxes," or "cells,". This discovery marked the beginning of cell theory (all living things are composed of cells).
Anton van Leeuwenhoek
Dutch merchant and mateur scientist Anton van Leeuwenhoek was probably the firs to actually observe live microorganisms through the magnifying lenses of more than 400 microscopes he constructed. Did detailed drawings of "animalcules" in rainwater, in his
Spontaneous Generation
Until second half of the nineteenth century, many scientists and philosophers believed that some forms of life could arise spontaneously from nonliving matter.
Francesco Redi (1668) did maggot experiment to disprove but people were not convinced (need fre
Biogenesis
Coined by German scientist Rudolf Virchow who challenged idea of spontaneous generation. Claim that living cells an arise only from preexisting living cells. Arguments about spontaneous generation continued until 1861, when the issue was resolved by the F
Louis Pasteur
French scientist who disproved the theory of spontaneous generation with his S-shaped curved beef broth experiment. He showed that microorganisms can be present in nonliving matter and that life can be destroyed by heat, forming the basis of ASEPTIC TECHN
Fermentation
Microorganisms called yeasts convert the sugars to alcohol in the absence of air. Discovered by Louis Pasteur, this process is used to make wine and beer. Souring and spoilage are caused by different microorganisms called bacteria. In the presence of air,
Pasteurization
Process invented by Pasteur to reduce spoilage and kill potentially harmful bacteria in milk as well as in some alcoholic drinks.
Germ Theory of Disease
Theory that microorganisms might cause disease.
Chemotherapy
Using chemical substances to treat diseases
Paul Ehrlich
German physician who came up with "salvarsan", an arsenic derivative effective against syphilis.
Alexander Fleming
Scottish physician and bacteriologist almost tossed out some culture plates contaminated by mold, but noticed a round spot where bacterial growth was inhibited. Mold was identified as Penicillium chrysogenum. In 1928, he named teh mold's active inhibitor
Bacteriology
The study of badteria which began with van Leeuwenhock's first examination of tooth scrapings.
Mycology
The study of fungi, which includes medical, agricultural, and ecological branches.
Parasitology
The study of protozoa and parasitic worms.
Genomics
Study of all of an organism's genes
Immunology
The study of immunity, dating back in Western culture to Jenner's first vaccine in 1796.
Virology
The study of viruses.
Paul Berg
Late 1960s; showed that fragments of human or animal DNA (genes) that code for important proteins can be attached to bacterial DNA. The resulting hybrid was teh first example of recombinant DNA. When recombinant DNA is inserted into bacteria (and other mi
George W. Beadle & Edward L. Tatum
Demonstrated relationship btw genes adn enzymes.
James Watson & Francis Crick
Proposed model for teh structure and replication of DNA.
Beijerinck & Winogradsky
Works help to open up field of microbial ecology, teh study of teh relationship btw microorganisms and their environment.