The correct answer is option (D) A sandwich is digested and converted to carbon dioxide and water.
Digestion is a catabolic process of breakdown of complex food substances into simpler nutrients releasing energy. In the process of digestion of a sandwich, the carbohydrates are broken down into simpler sugars in presence of enzymes releasing water, carbon dioxide and energy in the form of adenosine triphosphate (ATP). This ATP is the reserved energy currency and also used for the growth, repair and replacement of cells.
The products and reactants of each cycle are connected. reactants of photosynthesis (6O2 and C6H12O6) are recycled as products in cellular respiration which produces 6H2O 6CO2 and energy to fuel photosynthesis
