Step 1: Begin by understanding the photosynthesis reaction. Photosynthesis is the process by which plants convert carbon dioxide (CO₂) and water (H₂O) into glucose (C₆H₁₂O₆) and oxygen (O₂) using sunlight energy. The general equation is: .
Step 2: Analyze the given equations. The first two equations represent variations of the photosynthesis reaction. The first includes water molecules on both sides, while the second simplifies the reaction by omitting the water produced. Both are valid representations of photosynthesis.
Step 3: Examine the third equation: . This equation represents cellular respiration, the reverse of photosynthesis, where glucose and oxygen are broken down to produce carbon dioxide, water, and energy.
Step 4: Evaluate the fourth equation: . This equation is a simplified representation of photosynthesis, where (CH₂O) represents a carbohydrate unit.
Step 5: Conclude that the third equation does not represent photosynthesis but rather cellular respiration. The other equations are valid representations of photosynthesis, either in simplified or detailed forms.