Lysosome
STructure and function
Within eukaryotic cells are specialized vesicles called lysosomes that contain digestiveenzymes. These enzymes break down foreign material which may enter the cell. The name lysosome means "releasing body" and their enzymes cause "lysis" or disintegration of certain materials. They can be used to break down worn-out cellular components or bacteria engulfed by the cell. The enzymes they contain are so powerful that they can kill their host cell if released, so in normal cells they remain contained within the lysosome's membrane.
Phagocytosis
Phagocytosis (from Ancient Greek φαγεῖν (phagein) , meaning "to devour", κύτος,(kytos) , meaning "cell", and -osis, meaning "process") is the cellular process of engulfing solid particles by the cell membrane to form an internal phagosome byphagocytes and protists. Phagocytosis was revealed by Ilya Mechnikov in 1882. Phagocytosis is a specific form of endocytosis involving the vesicular internalization of solids such as bacteria, and is, therefore, distinct from other forms of endocytosis such as the vesicular internalization of various liquids. Phagocytosis is involved in the acquisition of nutrients for some cells, and, in the immune system, it is a major mechanism used to remove pathogens and cell debris. Bacteria, dead tissue cells, and small mineral particles are all examples of objects that may be phagocytosed.