Lysosome

• Membranous sac of hydrolytic enzymes that digest macromolecules • Enzymes in lysosomes work best in acidic environments (like in the lysosome itself) • Lysosomal enzymes not very active in cytosol, since pH is too high • Lysosomes digest in many circumstances – Amoebas and other unicellular eukaryotes feed by engulfing smaller organisms or food particles → PHAGOCYTOSIS – Food vacuole formed fuses with lysosome for digestion • Macrophages (found in humans) carry out phagocytosis -White blood cells engulf and destroy bacteria • Lysosomes also recycle the cell’s own organic material