Final answer:
Photosynthesis and cellular respiration involve regrouping atoms in chemical reactions to form different products. In photosynthesis, carbon dioxide and water combine to form glucose and oxygen. In cellular respiration, glucose and oxygen are broken down to produce carbon dioxide, water, and ATP.
Step-by-step explanation:
The atoms that make up the reactants in photosynthesis and cellular respiration are regrouped into different products through the chemical reactions involved. In photosynthesis, carbon dioxide and water are the reactants that combine to form glucose and oxygen as the products. This process occurs in the chloroplasts of eukaryotic cells. In cellular respiration, glucose and oxygen are the reactants that are broken down to produce carbon dioxide, water, and ATP (adenosine triphosphate) as the products. This process occurs in the mitochondria of eukaryotic cells.