What does intracellular mean?
Intracellular is a technical adjective describing something located, occurring, or taking place inside a cell. It commonly appears in discussions of cell biology, physiology, medicine, and pharmacology: an intracellular enzyme, for example, is an enzyme located within a cell, while an intracellular concentration refers to the amount of a substance present inside it. The term is also used for processes that occur within cells, such as intracellular communication, signalling, transport, and infection by pathogens that enter cells. Its principal contrast is with extracellular, which describes material or processes outside cells or in the spaces between them. Although intracellular can be understood in everyday language, it is most common in scientific and medical writing. The related adverb intracellularly is used when describing an action or condition that occurs within a cell.
adjectiveLocated or occurring within a cell, especially within the interior of a cell rather than between cells or outside them.
- Existing, occurring, or taking place within a cell.
"The drug acts by inhibiting an intracellular enzyme."
"Calcium levels changed rapidly in the intracellular space."
"Researchers used a fluorescent marker to study intracellular transport."
A cell has its own inner world: reactions within that space are intracellular, while signals passing between cells are extracellular.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Where does intracellular come from?
The word combines the Latin-derived prefix intra-, meaning “within,” with cellular, which relates to cells. The prefix intra- is itself built from the Latin word for “within,” while cellular developed through Latin and French from cell, ultimately referring to a small space or unit. The combined form has been used in scientific English since the development of modern cell biology.
Related word forms
How intracellular is actually used
This is primarily a technical term used in biology, medicine, pharmacology, and cell biology. It is normally used attributively before a noun, as in “intracellular fluid.”
Easily confused with intracellular
Intracellular describes something within a cell, whereas extracellular describes something outside a cell or between cells.