Cell excretion is the process by which a cell gets rid of waste and toxins through its cell membrane. The main parts involved are the vacuoles, which are small pockets that store waste, and lysosomes, which break down larger waste molecules. Approximately 600 million years ago, cells began using vacuoles to dispose of waste near the cell membrane, which would then encapsulate the waste and expel it from the cell. This process protects the cytoplasm and prevents unwanted materials from entering the cell.