What is meant by "cell metabolism"?

Cell metabolism refers to all the chemical reactions that occur within a cell, encompassing a wide variety of processes that enable the cell to grow, reproduce, maintain its structures, and respond to environmental changes. This includes both the breakdown of molecules to release energy (catabolic reactions) and the synthesis of compounds needed for the cell's function and growth (anabolic reactions).

The understanding of cell metabolism is crucial because it illustrates how cells convert food into energy, how they utilize that energy for various functions, and how they synthesize necessary biological molecules. This holistic view is what sets it apart from the other options, which only focus on specific aspects of what happens within cells rather than the comprehensive set of reactions that define metabolism.