Metabolism can be defined as the ________.

• A. process by which cells break down glucose to produce ATP only
• B. sum of all chemical reactions that occur within a living organism
• C. synthesis of macromolecules from monomers
• D. conversion of light energy into chemical energy

Answer: (B)

Verified step by step guidance

1. Step 1: Begin by understanding the term 'metabolism.' Metabolism refers to all the chemical reactions that occur within a living organism to maintain life. It includes both anabolic (building up) and catabolic (breaking down) processes.
2. Step 2: Analyze the options provided in the question. The first option, 'process by which cells break down glucose to produce ATP only,' describes a specific metabolic pathway (cellular respiration) but does not encompass the entirety of metabolism.
3. Step 3: Evaluate the second option, 'sum of all chemical reactions that occur within a living organism.' This definition aligns with the broad scope of metabolism, which includes all chemical reactions, both anabolic and catabolic.
4. Step 4: Consider the third option, 'synthesis of macromolecules from monomers.' This describes an anabolic process, which is a part of metabolism, but it does not represent the full definition of metabolism.
5. Step 5: Review the fourth option, 'conversion of light energy into chemical energy.' This describes photosynthesis, a specific metabolic process in autotrophs, but it does not define metabolism as a whole. Based on the analysis, the correct answer is the second option.