Agar
A polymer of galactose that is used as a gelling agent.
Antibiotic
A molecule that can kill or inhibit the growth of selected microorganisms.
Archaea
One of the three domains of life, consisting of organisms with a last common ancestor not shared with members of Bacteria or Eukarya. Organisms are prokaryotic (lacking nuclei, unlike eukaryotes) and possess ether-linked phospholipid membranes (unlike bac
Archaeon
pl. archaea A prokaryotic organism that is a member of the domain Archaea, distinct from bacteria and eukaryotes.
Aseptic
Free of microbes.
Autoclave
A device that uses pressurized steam to sterilize materials by raising the temperature above the boiling point of water at standard pressure.
Bacteria
One of the three domains of life, consisting of organisms with a last common ancestor not shared with members of Archaea or Eukarya. Organisms are prokaryotic (lacking nuclei, unlike eukaryotes) and possess ester-linked phospholipid membranes (unlike arch
Bacterium
pl. bacteria A prokaryotic organism that is a member of the domain Bacteria.
Biofilm
A community of microbes growing on a solid surface.
Chain of infection
The serial passage of a pathogenic organism from an infected individual to an uninfected individual, thus transmitting disease.
Chemiosmotic theory
A theory stating that the products of oxidative metabolism store their energy in an electrochemical gradient that can drive cell processes such as ATP synthesis.
Chemolithotroph
An organism that oxidizes inorganic compounds to yield energy and reduce carbon dioxide.
Colony
A visible cluster of microbes on a plate, all derived from a single founding microbe.
DNA sequencing
A technique to determine the order of bases in a DNA sample.
Electron microscope
A microscope that obtains high resolution and magnification by focusing electron beams on samples using magnetic lenses.
Endosymbiont
An organism that lives as a symbiont inside another organism.
Enrichment culture
The use of selective growth media to allow only certain microbes to grow.
Eukarya
One of the three domains of life, consisting of organisms with a last common ancestor not shared with members of Archaea or Bacteria. Cells possess nuclei, unlike cells of bacteria and archaea.
Eukaryote
An organism whose cells contain a nucleus. All eukaryotes are members of the domain Eukarya.
Fermentation
Also called fermentative metabolism. The production of ATP via substrate-level phosphorylation, using organic compounds as both electron donors and electron acceptors.
Genome
The complete genetic content of an organism. The sequence of all the nucleotides in a haploid set of chromosomes.
Germ theory of disease
The theory that many diseases are caused by microbes.
Kochs postulates
Four criteria that should be met for a microbe to be designated the causative agent of an infectious disease.
Lithotroph
An organism that oxidizes inorganic compounds to yield energy and reduce carbon dioxide.
Microbe
An organism or virus too small to be seen with the unaided human eye.
Monophyletic
Diverging from a common ancestor.
Nitrogen fixation
The ability of some prokaryotes to reduce inorganic diatomic nitrogen gas (N2) to two molecules of ammonium ion (2 NH4+).
Petri dish
Also called pour plate. A round dish with vertical walls covered by an inverted dish of slightly larger diameter. The smaller dish can be filled with a substrate for growing microbes.
Photosynthesis
The metabolic ability to absorb and convert solar energy into chemical energy for biosynthesis; a precise definition includes CO2 fixation.
Polyphyletic
Having multiple evolutionary origins.
Prokaryote
An organism whose cell or cells lack a nucleus; includes both bacteria and archaea.
Pure culture
A culture containing only a single strain or species of microorganism. A large number of microorganisms all descended from a single individual cell.
Spontaneous generation
The theory, much debated in the nineteenth century, that under current Earth conditions life can arise spontaneously from nonliving matter.
Ultracentrifuge
A machine that exposes samples to high centrifugal forces and can be used to separate subcellular components.
Vaccination
Exposure of an individual to a weakened version of a microbe to provoke immunity and prevent development of disease upon reexposure.
Virus
A non-cellular particle containing a genome that can replicate only inside a cell.
Microbiology
the study of microscopic organisms
What are the different types of microbes?
Cellular-bacteria, algae, protozoan, fungi
Acellular-virus, prion, viroids
What is the unit of measurement for microbes?
micrometer
.001 mm
10^-6 meter
What are Koch's postulates?
1. Suspected agent is only found in sick individual, not a healthy individual.
2. Suspected agent must be able to be isolated from the sick individual and grown in pure form.
3. The suspected agent must be introduced to a healthy individual and produce th
When can we not satisfy Koch's postulates?
-Individuals may carry a pathogen, but not exhibit sickness (carrier).
-There is more than one individual responsible for the disease.
-Lack of an appropriate experimental host.
-Organism itself does not cause disease, but a gene that it carries is respon
What are roles that microbes play that affect human activities?
Medicine-antibiotics, sickness
Food-fermentation
Industry
Environment
What were the original 5 kingdom system based on?
Cell structure and mode of nutrition
What were the original 5 kingdoms?
Monera, protista, fungi, plants, animals
What is the 3 domain system based on?
Phylogenetic analysis of 16 SrRNA
What re the 3 domains?
Eucarya, Bacteria, Archaea
What is the endosymbiotic theory?
Mitochondria and chloroplasts in eukaryotic cells are a result of endosymbiosisfrom prokaryotic cells engulfed by proto-eukaryotes. M and C provide energy, host provides protection.
What are the contributions of Leuwenhoek?
Designed simple microscopes, described microorganisms, scientific process of verification.
What are the contributions of Pasteur?
Showed that providing oxygen does not enable spontaneous generation with swan neck flask, discovered that specific types of microbes yield different products due to the metabolic properties of the organism, developed pastuerization, microbial basis of fer
What are the contributions of Koch?
Koch's postulates, pure culture technique, culture of organisms on agar, germ theory
Pasteurization
partial sterilization of foods at a temperature that destroys harmful microorganisms without major changes in the chemistry of the food
Vaccine
immunogen consisting of a suspension of weakened or dead pathogenic cells injected in order to stimulate the production of antibodies
Antibody
a disease-fighting protein created by the immune system in response to the presence of a specific antigen
Antigen
A protein that, when introduced in the blood, triggers the production of an antibody
Attenuation
dilution or weakening of virulence of a microorganism, reducing or abolishing pathogenicity
Pathogen
a virus or organism that can cause disease
Humoral immunity
immunity against antigens and pathogens in the body fluids.
Cellular immunity
an immune response from the direct action of immune cells
Endosymbiosis
a mutually beneficial relationship in which one organism lives within another
Domain
most inclusive taxonomic group, larger than kingdom; three exist - bacteria, archaea, eukaryota