Lysosomes are vesicles filled with digestive enzymes that perform which roles?

• A. Energy production
• B. Cleanup and recycling
• C. Storage
• D. Digestion of proteins

Answer: (B)

Lysosomes function as the cell’s waste disposal and recycling centers. They house acid hydrolases that break down a wide range of macromolecules—proteins, lipids, nucleic acids, and carbohydrates—as well as damaged organelles. The enzymes work best in the acidic interior of the lysosome, and the membrane keeps the dangerous contents away from the rest of the cell. Through autophagy, damaged components are sequestered and delivered to lysosomes for degradation, and through endocytosis they digest material taken up from outside the cell. The resulting basic molecules—amino acids, sugars, nucleotides—are reused, supporting cellular maintenance and renewal. That broad cleanup-and-recycling role best captures what lysosomes do, more so than simply producing energy, storing materials, or digesting proteins alone.