Which broad term includes all chemical reactions that occur within body cells?

Which broad term includes all chemical reactions that occur within body cells?

• A. Metabolism
• B. Digestion
• C. Excretion
• D. Reproduction

Answer: (A)

Metabolism is the broad term for all chemical reactions that occur within body cells. These reactions include breaking down molecules to release energy (catabolic processes) and using energy to build new, larger molecules (anabolic processes). Enzymes act as catalysts to speed these reactions, and molecules like ATP serve as the energy currency that powers cellular activities. For example, glycolysis in the cytoplasm breaks down glucose to produce ATP, while protein synthesis builds proteins from amino acids. This overall umbrella covers the wide range of intracellular chemistry that keeps cells functioning. Digestion refers to breaking down food in the digestive tract, excretion is the removal of waste from the body, and reproduction involves making new cells or organisms; none of these alone captures all the chemical work happening inside cells.

Metabolism is the broad term for all chemical reactions that occur within body cells. These reactions include breaking down molecules to release energy (catabolic processes) and using energy to build new, larger molecules (anabolic processes). Enzymes act as catalysts to speed these reactions, and molecules like ATP serve as the energy currency that powers cellular activities. For example, glycolysis in the cytoplasm breaks down glucose to produce ATP, while protein synthesis builds proteins from amino acids. This overall umbrella covers the wide range of intracellular chemistry that keeps cells functioning. Digestion refers to breaking down food in the digestive tract, excretion is the removal of waste from the body, and reproduction involves making new cells or organisms; none of these alone captures all the chemical work happening inside cells.