Which structure is responsible for digesting worn-out cellular parts?

The structure responsible for digesting worn-out cellular parts is the lysosome. Lysosomes are membrane-bound organelles that contain enzymes capable of breaking down various types of biomolecules. Their primary function is to process cellular waste and recycle components, which includes digesting damaged or obsolete cellular materials. By doing so, lysosomes help maintain cellular health and function by ensuring that waste does not accumulate within the cell, thereby preventing potential damage or dysfunction.

Other structures mentioned do not play this role: ribosomes are involved in protein synthesis, mitochondria are primarily responsible for energy production, and the nucleus contains the cell's genetic material and is involved in regulating gene expression and cell division. Each of these organelles has distinct and essential functions, but it is the lysosome that specializes in the degradation and recycling of worn-out cellular components.