phag

Phag is a combining form used in biological terminology derived from the Greek phagein, meaning “to eat.” In scientific usage, phag- denotes ingestion or engulfment of material by a cell or organism. It is most commonly encountered in terms describing cellular processes such as phagocytosis, the process by which a cell engulfs solid particles, including microbes and debris.

In biology, cells that perform phagocytosis are called phagocytes; key examples include macrophages and neutrophils in animals. The material internalized during phagocytosis is enclosed within a phagosome, a membrane-bound vesicle. The phagosome then typically fuses with lysosomes to form a phagolysosome, where the ingested contents are digested.

The phag- root also appears in related contexts to describe the action of engulfment and in naming specialized organelles and processes, such as phagosome maturation and various pathways of endocytosis. The root is often contrasted with phage, a related term also derived from the same ancient Greek root but referring to viruses that infect bacteria.

In summary, phag as a root signals eating or engulfment in biological processes, most notably in phagocytosis and phagocytic cells.