phagocytosis

More generally, phagocytosis in the capture of a solid external to a cell in a membrane which is then brought inside a cell by active transport.

To add to Eos's node, phagocytosis is not just for ingesting food. It is used by certain types of white blood cells (eg, marcophages) as a defensive mechanism in the human (an probably many other animals') immune response. These cells extend pseudopodia to surround pathogens and then engulf them and break them down using lytic enzymes.

Some types of really nasty pathogens are resistant to the lytic enzymes and can live and reproduce inside white blood cells.

1. The process by which a cell is engulfed and broken down by another for purposes of defense or sustenance.
   
   
2. The uptake of extracullular materials by the formation of a pocket from the cellular membrane and its subsequent pinching off. Compare endocytosis and pinocytosis.

From the BioTech Dictionary at http://biotech.icmb.utexas.edu/. For further information see the BioTech homenode.