Microbiology terms - A


icosahedron
A geometrical shape occurring in many virus particles, with 20 triangular faces and 12 corners.
immobilized enzyme
An enzyme attached to a solid support over which substrate is passed and is converted into product.
immune
1. An adjective, when a human or animal body which is able to resist infectious disease because of either previous infection, immunization/vacination, or contact with the immunogen/antigen, then the human or animal is immune to this disease .

2. As a noun, the state of immunity.

immune response
The specific reactions induced in the human or animal body due to the contact with foreign material. The foreign material which induces the immune response is called an immunogen or antigen. The immunse response may involve either antibody production, the activation of T cells or both.
immunity
The ability of a (human or animal) body to resist infection by microorganisms or their harmful products such as toxin. There are several types of immunities (ways of obtaining immunity): inherited immunity, acuired immunity (including active immunity and passive immunity), and autoimmunity.
immunization
Induction of specific immunity by injecting antigens, antibodies, or immune cells.
immunoblot (Western blot)
Detection of proteins immobilized on a filter by complementary reaction with specifc antibody. Compare with Southern and northern blot.
immunogen
A substance which is capable of eliciting (inducing) immune response. An immunogen usually has a fairly high molecular weight (usually greater than 10,000), thus, a variety of macromolecules such as proteins, lipoproteins, polysaccharides, some nucleic acids, and certain of the teichoic acids, can act as immunogens. Compare with antigen.
immunoglobulin
Antibody
immunologic memory
The ability to rapidly produce large quantities of specific immune cells after subsequent exposure to a previously encountered antigen.
immonology
The study of immunity and immune system.
in vitro
Literally means "in glass", away from a living organism; it is used to describe whatever happens in a test tube or other receptacle, as opposed to in vivo. When a study or an experiment is done outside the living organism, i.e., in test tube, it is said it's done in vitro.
in vivo
In the body, in a living organism, as opposed to in vitro; when a study or an experiment is done in the living organism, it is said this is done in vivo.
incidence
In reference to disease transmission, the number of cases of the disease in a specific subset of the population.
induced enzyme
An enzyme subject to induction.
induction
The process by which an enzyme is synthesized (induced) in response to the presence of an external substance, the inducer.
infection
Growth of an organism within the body.
infection thread
In the formation of root nodules, a cellulosic tube through which Rhizobium cells can travel to reach and infect root cells.
inflammation
Characteristic reaction to foreign particles and noxious stimuli, resulting in redness, swelling, heat, and pain.
inhibition
Prevention of growth or function.
inoculum
Material used to initiate a microbial culture.
insertion
A genetic phenomenon in which a piece of DNA is inserted into the middle of a gene.
insertion sequence (IS element)
The simplest type of transposable element. Has only genes involved in transposition.
integration
The process by which a DNA molecule becomes incorporated into another genome.
interferon
A protein produced by cells as a result of virus infection which interferes with virus replication.
interspecies hydrogen transfer
The process in which organic matter is degraded anaerobically by the interaction of several groups of microorganisms in which hydrogen production and hydrogen consumption are closely coupled among species.
intron
The intervening noncoding sequence in a split gene. Contrasted with exon, the coding sequence.
invasiveness
Degree to which an organism is able to spread through the body from a focus of infection.
ionophore
A compound which can cause the leakage of ions across membranes.
isoenzyme (isozyme)
When two different enzymes catalyze the same reaction(s), they are isoenzyme to each other. Isoenzymes could differ from each other in their primary structure or electrophoretic mobility.
isolation
1. Any procedure in which a given species of organism, present in a particular sample or environment, is obtained in pure culture.
isotope
Different form of the same element containing the same number of protons and electrons, but differing in the number of neutrons.
isozyme
See isoenzyme.

Compiled by Tsute Chen, Converted by Ben Hoyt