Microbiology terms - A


ecology
Study of the interrelationships between organisms and their environments.
ecosystem
A community of organisms and their natural environment.
electron acceptor
A substance that accepts electrons during an oxidation-reduction reaction. An electron acceptor is an oxidant.
electron donor
A substance that donates electrons in an oxidation-reduction reaction. An electron donor is a redutant.
electron-transport phosphyrylation
Synthesis of ATP involving a membrane-associated electron transport chain and the creation of a proton-movitve force. Also called oxidative phosphorylation.
electrophoresis
Separation of charged molecules (e.g. nucleic acids) in an electrical field.
electroporation
The use of an electrical pulse to enable cells to take up DNA.
ELISA
Enzyme-linked immunosorbent assay. An immunoassay that uses specific antibodies to detect antigens or antibodies in body fluids. The antibody-containing complexes are visualized through enzyme coupled to the antibody. Addition of substrate to the enzyme-antibody-antigen complex results in a colored product.
Embden-Meyerhof-Parnas pathway (Embden-Meyerhof pathway; EMP pathway)
A pathway that degrades glucose to pyruvate; the six-carbon stage converts glucose to fructose-1,6-bisphosphate, and the three-carbon stage produces ATP while changing glyceraldehyde-3-phosphate to pyruvate. Compare with Entner-Doudoroff pathway.
Entner-Doudoroff pathway (ED pathway)
A pathway that converts glucose to pyruvate and glyceraldehyde-3-phosphate by producing 6-phosphogluconate and then dehydrating it..
endemic
A disease that is constantly present in low numbers in a population. Compare with epidemic.
endergonic
A chemical reaction requiring input of energy to proceed.
endocytosis
A process in which a particle such as a virus is taken intact into an animal cell. Phagocytosis and pinocytosis are two kinds of endocytosis.
endoplasmic reticulum (ER)
An extensive array of internal membranes in eukaryotes.
endospore
A differentiated cell formed within the cells of certain gram-positive bacteria and extremely resistant to heat as well as to other harmful agents.
endosymbiosis
The hypothesis that m.mitochondria and chloroplasts are the descendants of ancient prokaryotic organisms from the domain Bacteria.
endotoxin
A toxin not released from the cell; bound to the cell surface or intracellular. Compare with e.exotoxin.
enrichment culture
Use of selective culture media and incubation conditions to isolate microorganisms directly from nature.
enterics
The common name for bacteria in the family Enterobacteriaceae.
enteric bacteria
A large group of gram-negative rod-shaped Bacteria characterized by a facultatively aerobic metabolism. Many of them are commonly found in the intestines of animals.
enterotoxin
A toxin affecting the intestine.
enzyme
A protein functioning as a catalyst in living organisms, which promotes specific reactions or groups of reactions.
epidemic
A disease occurring in an unusually high number of individuals in a population at the same time. Compare with endemic.
epidemiology
The study of the incidence and prevalence of disease in populations.
epitope
Antigenic determinant.
Eubacteria
An old term for the Bacteria
Eukarya
The phylogenetic domain containing all eukaryotic organisms.
eukaryote
A cell or organism having a unit membrane-bound (true) nucleus and usually other organelles.
evolutionary distance
In phylogenetic trees, the sum of the physical distance on a tree separating organisms; this distance is inversely proportional to evolutionary relatedness.
exergonic reaction
A chemical reaction that proceeds with the liberation of energy.
exon
The coding sequences in a split gene. Contrast with intron, the intervening noncoding region.
exotoxin
A toxin released extracellularly. Compare with endotoxin.
exponential growth
Growth of a microorganism where the cell number doubles within a fixed time period.
exponential phase
A period during the growth cycle of a population in which growth increases at an exponential rate.
expression
The ability of a gene to function within a cell in such a way that the gene products is formed.
expression vector
A clonng vector that contains the necessary regulatory sequences to allow transcription and translation of a cloned gene or genes.
extreme halophile
An organism whose growth is dependent on large amounts (generally >10%) of NaCl.

Compiled by Tsute Chen, Converted by Ben Hoyt