Metabolic terminology: digestive reactions in which large biomolecules are broken down into smaller units are referred to as what?

Introduction / Context:
Metabolism comprises two complementary sets of reactions. Correctly distinguishing catabolism from anabolism underpins understanding of energy flow, carbon flux, and how cells balance growth with maintenance.

Given Data / Assumptions:

• Focus is on “digestive” breakdown of macromolecules to smaller units.
• We are to select the standard biochemical term.
• Assume typical cellular conditions.

Concept / Approach:
Catabolism breaks down complex molecules (for example, proteins to amino acids, polysaccharides to sugars, lipids to fatty acids and glycerol), often releasing energy captured as ATP or reducing equivalents (NADH, FADH2). Anabolism builds complex molecules and typically requires energy input.

Step-by-Step Solution:

Verification / Alternative check:
Textbook definitions: catabolism = degradative, energy-yielding; anabolism = biosynthetic, energy-requiring. This matches the question’s description.

Why Other Options Are Wrong:

• Anabolism and biosynthesis: opposite direction (building).
• Metabolism: umbrella term that includes both; too vague.

Common Pitfalls:
Assuming all catabolic steps directly make ATP; some only generate reducing power later used for ATP via oxidative phosphorylation.

Final Answer:
catabolism