Photosynthesis & Cellular Respiration
Photosynthesis is the process by which green plants use sunlight, carbon dioxide, and water to produce glucose and oxygen, storing energy in chemical bonds. Cellular respiration is the process by which cells break down glucose and oxygen to release energy, producing carbon dioxide and water as byproducts. Together, these processes form a cycle that sustains life: photosynthesis captures energy from the sun, while cellular respiration releases that energy for use by living organisms.
Photosynthesis & Cellular Respiration
Photosynthesis is the process by which green plants use sunlight, carbon dioxide, and water to produce glucose and oxygen, storing energy in chemical bonds. Cellular respiration is the process by which cells break down glucose and oxygen to release energy, producing carbon dioxide and water as byproducts. Together, these processes form a cycle that sustains life: photosynthesis captures energy from the sun, while cellular respiration releases that energy for use by living organisms.
💡 Key Takeaways
- Identify the inputs and outputs of photosynthesis (sunlight, CO2, water → glucose and O2) and where it occurs in plant cells.
- Explain the two main photosynthesis stages—light-dependent reactions and the Calvin cycle—and the role of ATP and NADPH in sugar production.
- Describe cellular respiration as the process of converting glucose and oxygen into ATP, with CO2 and water as byproducts, outlining glycolysis, the Krebs cycle, and oxidative phosphorylation.
- Compare photosynthesis and cellular respiration as opposite energy processes in living systems, and distinguish aerobic from anaerobic respiration.
❓ Frequently Asked Questions
What is photosynthesis?
Photosynthesis is the process by which green plants use sunlight, carbon dioxide, and water to produce glucose (stored chemical energy) and oxygen.
What are the main inputs and outputs of photosynthesis?
Inputs: light energy, CO2, H2O. Outputs: glucose and O2.
What is cellular respiration?
Cellular respiration is the process by which cells break down glucose with oxygen to release energy (ATP), producing CO2 and H2O as byproducts.
What are the main stages of cellular respiration and where do they occur?
Glycolysis occurs in the cytoplasm; the Krebs cycle and oxidative phosphorylation (electron transport chain) occur in mitochondria.
How are photosynthesis and cellular respiration connected?
They form a cycle: photosynthesis uses CO2 and H2O to make glucose and O2; respiration uses glucose and O2 to release energy and produce CO2 and H2O. The outputs of one process feed the inputs of the other.