What best describes cellular metabolism?

Cellular metabolism encompasses the total biochemical processes that occur within a cell, which includes both the synthesis (anabolism) and degradation (catabolism) of various molecules. This comprehensive description captures the dynamic nature of metabolism as it involves all chemical reactions that maintain cellular function and energy.

In cellular metabolism, various pathways work in concert to convert nutrients into energy, build cellular components, and break down waste products. For instance, metabolism includes glycolysis, the citric acid cycle, oxidative phosphorylation, and other metabolic pathways that facilitate the transformation of substances essential for life.

The other choices do not encompass the full scope of cellular metabolism. While the degradation of proteins and carbohydrates is a part of metabolic processes, it represents only a subset of the overall metabolic pathways that include synthesis as well as breakdown. Describing metabolism as a single pathway of energy production limits its breadth, as metabolism includes many interacting pathways beyond just energy production. Similarly, cell division and replication are processes that may occur as a result of metabolism but are not synonymous with the entire metabolic process itself. Therefore, the choice that captures the entirety of biochemical activity in the cell is the best representation of cellular metabolism.