What is the term for the process by which cells surround and digest certain particles?

The process by which cells surround and digest certain particles is known as phagocytosis. This specific form of endocytosis involves the engulfing of large particles, such as bacteria or dead cells, by specialized cells known as phagocytes. During phagocytosis, the cell membrane extends around the particle, eventually enclosing it within a vesicle called a phagosome. This phagosome then fuses with lysosomes — organelles filled with digestive enzymes — allowing the particle to be broken down and digested.

Phagocytosis is crucial for immune function, as it helps to eliminate pathogens and debris from the body, thereby maintaining overall health and homeostasis. The specificity of this process is unique compared to other forms of transport, such as exocytosis, which involves the expulsion of materials from the cell, or active transport, which is related to moving ions and molecules against their concentration gradient using energy.