Catabolic reactions are best described as which of the following?

Catabolic reactions are best described as which of the following?

• A. Builds larger molecules from smaller ones
• B. Stores energy in ATP
• C. Breaks down large molecules into smaller ones
• D. Occurs only in mitochondria

Answer: (C)

Catabolic reactions are the breakdown part of metabolism: they take large, complex molecules and split them into smaller ones, releasing energy in the process. That released energy is captured to form ATP, the cell’s main energy currency, which then powers other activities. So describing catabolic reactions as breaking down large molecules into smaller ones is the best fit. Some steps occur in the cytoplasm (like glycolysis), not just in mitochondria, and energy is produced rather than stored there; in contrast, anabolic pathways build larger molecules and require energy. An example is glycolysis, where glucose is split into smaller units, generating ATP and NADH.

Catabolic reactions are the breakdown part of metabolism: they take large, complex molecules and split them into smaller ones, releasing energy in the process. That released energy is captured to form ATP, the cell’s main energy currency, which then powers other activities. So describing catabolic reactions as breaking down large molecules into smaller ones is the best fit. Some steps occur in the cytoplasm (like glycolysis), not just in mitochondria, and energy is produced rather than stored there; in contrast, anabolic pathways build larger molecules and require energy. An example is glycolysis, where glucose is split into smaller units, generating ATP and NADH.