Which organelle would be most directly involved in intracellular digestion?

• A. Lysosomes
• B. Nucleolus
• C. Chloroplasts
• D. Ribosomes

Answer: (A)

Intracellular digestion is performed by lysosomes, which are membrane-bound organelles packed with hydrolytic enzymes that break down proteins, nucleic acids, lipids, and carbohydrates inside the cell. They fuse with vesicles containing material to be digested, such as phagosomes or autophagosomes, and the acidic environment inside lysosomes activates the enzymes to degrade the contents into reusable building blocks. The nucleolus is where ribosomal RNA is produced and ribosome assembly occurs, not digestion. Chloroplasts carry out photosynthesis, and ribosomes synthesize proteins. So the lysosome is the organelle most directly involved in intracellular digestion.