transduktio

Transduktio, in a biological context often translated as transduction, refers to processes in which information, material, or energy is transferred and transformed by a mediator or carrier. The term has several distinct but related uses in science.

One major sense is signal transduction, the cellular process by which an external signal is detected by a receptor and converted into a functional response inside the cell. This typically involves a receptor that binds a ligand, followed by a cascade of molecular events such as phosphorylation, second messenger production, and activation of transcription factors. The result is changes in metabolism, gene expression, or cell behavior. Receptors include G protein–coupled receptors, receptor tyrosine kinases, and ion channels, and the pathways are subject to regulation, feedback, and cross-talk with other signals.

Another important sense is genetic transduction in microbiology, the transfer of genetic material from one bacterium to another via a bacteriophage. In generalized transduction, phages package random fragments of the donor genome and deliver them to a recipient; in specialized transduction, genes near a phage integration site are transferred. Transduction contributes to horizontal gene transfer, microbial evolution, and the spread of traits such as antibiotic resistance. Core steps include phage infection, accidental packaging of donor DNA, infection of a new host, and recombination with the recipient genome.

Transduction can also refer to the conversion of one form of energy to another in sensory or engineering contexts, such as converting a physical stimulus into neural signals or vice versa. In all uses, the concept centers on a mediator enabling a change of state or form between systems.