Final answer:
The term for the sum of all chemical reactions in a cell or organism is metabolism, covering both energy-releasing catabolic reactions and energy-using anabolic reactions.
Step-by-step explanation:
The sum of all chemical reactions that occur in a cell or organism is called metabolism. This includes both catabolic reactions, which involve the breakdown of complex molecules into simpler ones releasing energy, and anabolic reactions, which build complex molecules from simpler ones and require energy. Metabolism is essential as it encompasses all the biochemical reactions that enable an organism to maintain life, manage energy, and sustain its functions.