Final answer:
Metabolism is the term for all chemical reactions in a living organism, including catabolic reactions that break down molecules for energy and anabolic reactions that build up new molecules. Option 1) Metabolism is the correct answer to the student's question.
Step-by-step explanation:
The overall word that refers to all the chemical reactions in a living organism is metabolism. Metabolic reactions are categorized into two types: catabolic reactions, which break down molecules to release energy, and anabolic reactions, which build up new molecules that living systems require. So, to answer the student's question, the correct option is 1) Metabolism.
Metabolism encompasses the thousands of coordinated chemical reactions that occur within cells to sustain life. Living things require energy to maintain internal conditions known as homeostasis, for growth, and for various other life processes. Through metabolic activities, living organisms transform energy by converting chemicals and energy into cellular components and conversely decompose organic matter to obtain that energy.
Catabolism and anabolism proceed simultaneously in living organisms, ensuring that they maintain their health and continue living. These processes involve not just exchanges of matter, but also of energy, which is crucial for the organism's survival.