Which one is true of photosynthesis and cellular respiration? Energy is stored in both photosynthesis and cellular respiration. However, photosynthesis can only happen in plants. In photosynthesis, carbon dioxide (CO2) and water (H2O) are required reactants. In cellular respiration, carbon dioxide (CO2) and water (H20) are products Photosynthesis releases ATP from glucose, but respiration does the opposite. Plants gather energy molecules, and cellular respiration requires light.
The Correct Answer and Explanation is :
The correct answer is: In photosynthesis, carbon dioxide (CO₂) and water (H₂O) are required reactants. In cellular respiration, carbon dioxide (CO₂) and water (H₂O) are products.
Explanation:
Photosynthesis and cellular respiration are complementary biological processes that maintain the flow of energy in ecosystems. While they involve different mechanisms and outcomes, they are interconnected through the carbon and energy cycles.
Photosynthesis occurs primarily in plants, algae, and some bacteria. It takes place in the chloroplasts, where light energy is used to convert carbon dioxide (CO₂) and water (H₂O) into glucose (C₆H₁₂O₆) and oxygen (O₂). The overall equation is:
[ 6CO₂ + 6H₂O + light \rightarrow C₆H₁₂O₆ + 6O₂ ]
Here, CO₂ and H₂O are the required reactants. Plants use chlorophyll to capture light energy, driving the process.
Cellular respiration, on the other hand, occurs in the mitochondria of nearly all living organisms (plants, animals, fungi, and many microorganisms). It involves breaking down glucose in the presence of oxygen to release energy in the form of ATP (adenosine triphosphate). Its equation is the reverse of photosynthesis:
[ C₆H₁₂O₆ + 6O₂ \rightarrow 6CO₂ + 6H₂O + energy (ATP) ]
Here, CO₂ and H₂O are the products.
Why the other options are incorrect:
- Photosynthesis can occur in algae and some bacteria, not just plants.
- ATP is not released during photosynthesis; it is generated in cellular respiration.
- Cellular respiration does not require light; it depends on chemical energy from glucose.
- Energy is stored in photosynthesis, but cellular respiration releases it.
This complementarity ensures energy and carbon flow through ecosystems, sustaining life.