Question

the image below models photosynthesis occurring in the chloroplast of a plant cell. in the model, the calvin cycle is the series of reactions through which sugar (c₆h₁₂o₆) is produced. the molecules atp and nadph transport energy from light to the calvin cycle.

based on this model, which statement best compares the amounts of energy in the reactants and products of photosynthesis?
a. since the process of photosynthesis makes new energy, the combined energy in the bonds of o₂ and c₆h₁₂o₆ is greater than that in the bonds of co₂ and h₂o.

b. since sugar stores the energy from light, the combined energy in the bonds of o₂ and c₆h₁₂o₆ is greater than that in the bonds of co₂ and h₂o.

Explanation:

• Option A is incorrect because energy cannot be created (photosynthesis converts light energy into chemical energy, not "make new energy").
• Option B is correct: Photosynthesis uses light energy to convert \( \text{CO}_2 \) and \( \text{H}_2\text{O} \) into \( \text{O}_2 \) and glucose (\( \text{C}_6\text{H}_{12}\text{O}_6 \)). Glucose stores the light energy as chemical energy, so the combined energy in \( \text{O}_2 \) and \( \text{C}_6\text{H}_{12}\text{O}_6 \) (products) is greater than in \( \text{CO}_2 \) and \( \text{H}_2\text{O} \) (reactants).

Answer:

B. Since sugar stores the energy from light, the combined energy in the bonds of \( \text{O}_2 \) and \( \text{C}_6\text{H}_{12}\text{O}_6 \) is greater than that in the bonds of \( \text{CO}_2 \) and \( \text{H}_2\text{O} \).