The structure responsible for breaking down waste products in a cell is the lysosome. Lysosomes contain digestive enzymes that facilitate the breakdown of biological macromolecules, such as proteins, lipids, and nucleic acids. These organelles play an essential role in cellular cleanup, recycling materials for reuse and maintaining cellular health. Dysfunction of lysosomes can lead to various diseases known as lysosomal storage disorders, emphasizing their importance in cellular metabolism and homeostasis.