Microbiology terms - R


radioimmunoassay
An immunological assay employing radioactive antibody or antigen for the detection of certain substances in body fluids.
radioisotope
An isotope of an element that undergoes spontaneous decay with the release of radioactive particles.
reaction center
A photosynthetic complex containing chlorophyll (or bacteriochlorophyll) and other components, within which occurs the initial electron transfer reactions of photophosphorylation.
reading-frame shift
See frameshift.
recalcitrant
Resistant to microbial attack.
recombinant DNA
A DNA molecule containing DNA originating from two or more sources.
recombination
Process by which genetic elements in two separate genomes are brought together in one unit.
redox
See oxidation-reduction reaction.
reduction
A process by which a compound accepts electrons to become reduced.
reduction potential
The inherent tendency of a compound to act as an electron donor or an electron acceptor. Measure in volts.
reductive dechlorination
Removal of Cl as Cl- from an organic compound by reducing the carbon atom from C-Cl to C-H.
regulation
Proceses that control the rates of synthesis of proteins. Induction and repression are examples of regulation.
regulon
A set of operons that are all controlled by the same regulatory protein (repressor or activator).
replacement vector
A cloning vector, such as a bacteriophage, in which some of the DNA of the vector can be replaced with foreign DNA.
replication
Conversion of one double-stranded DNA molecule into two identical double-stranded DNA molecules.
repression
The process by which the synthesis of an enzyme is inhibited by the presence of an external substance, the repressor.
repressor protein
A regulatory protein that binds to sepecific sites on DNA and blocks transcription.
reservoir
In epidemiology, the organism or environment that normally harbors a pathogen.
respiration
Catabolic reactions producing ATP in which either organic or inorganic compounds are primary electron donors and organic or inorganic compounds are ultimate electron acceptors.
Restriction endonucleases (restriction enzymes)
Enzymes that recognize and cleave specific DNA sequences, generating either blunt or single-stranded (sticky) ends.
retrovirus
Virus containing single-stranded RNA as its genetic material and which produces a complementary DNA by action of the enzyme reverse transcriptase.
reverse electron transport
The energy-dependent movement of electrons against the thermodynamic gradient to form a strong reductant from a weaker electron donor.
reverse transcriptase
The enzyme responsible for the process of reverse transcription.
reverse transcription
The process of copying information found in RNA into DNA.
rheumatic fever
An inflammatory autoimmune disease triggered by an immune response to infection by Streptococcus pyogenes.
rhizosphere
The region immediately adjacent to plant roots.
ribonucleic acid (RNA)
A polymer of nucleotides connected via a phosphate-ribose backbone, involved in protein synthesis.
robisomal RNA (rRNA)
Types of RNA found in the ribosome; some participate actively in the process of protein synthesis.
ribosome
A cytoplasmic particle composed of ribosomal RNA and protein, which is part of the protein-synthesizing machinery of the cell.
ribozyme
An RNA molecule that can catalyze a chemical reaction.
rickettsias
Obligate intracellular parasites which cause a variety of disease, including typhus and Rocky Mountain spotted fever.
RNA life
A hypothetical life form lacking DNA and protein which may have existed on early earth and in which RNA served both a genetic coding and a catalytic function.
RNA processing
The conversion of a precursor RNA into its mature form.
rod
See bacillus.
root nodule
A tumor-like growth on plant roots that contains symbiotic nitrogen-fixing bacteria.
rumen
The forestomach of ruminant animals in which cellulose digestion occurs.

Compiled by Tsute Chen, Converted by Ben Hoyt