In this chapter, we will address the following questions: what is photosynthesis? How does photosynthesis convert light energy into chemical energy? How is chemical energy used to synthesize carbohydrates? How do plants adapt to the Inefficiencies of photosynthesis? How is photosynthesis connected to other metabolic pathways in plants? | Photosynthesis: Energy from Sunlight 8 Photosynthesis: Energy from Sunlight What Is Photosynthesis? How Does Photosynthesis Convert Light Energy into Chemical Energy? How Is Chemical Energy Used to Synthesize Carbohydrates? How Do Plants Adapt to the Inefficiencies of Photosynthesis? How Is Photosynthesis Connected to Other Metabolic Pathways in Plants? What Is Photosynthesis? Photosynthesis: “synthesis from light” The broad outline: Plants take in CO2 and release water and O2 Light is required Figure The Ingredients for Photosynthesis What Is Photosynthesis? Ruben and Kamen determined the source of O2 released during photosynthesis by using radioisotope tracers. Figure Water Is the Source of the Oxygen Produced by Photosynthesis What Is Photosynthesis? Two pathways: Light reactions: light energy converted to chemical energy (in ATP and NADPH + H+) Light-independent reactions: use the ATP and NADPH + H+ plus CO2 to produce sugars Figure An Overview of Photosynthesis How Does Photosynthesis Convert Light Energy into Chemical Energy? Light is a form of electromagnetic radiation, which comes in discrete packets called photons and behave as particles. Light also behaves as if propagated as waves. Energy of a photon is inversely proportional to its wavelength. How Does Photosynthesis Convert Light Energy into Chemical Energy? When a photon meets a molecule it can be: Scattered or reflected Transmitted or pass through the molecule Absorbed—the molecule acquires the energy of the photon. The molecule goes from ground state to excited state. Figure Exciting a Molecule (A) Figure Exciting a Molecule (B) Energy from the photon boosts an electron into another shell How Does Photosynthesis Convert Light Energy into Chemical Energy? Photons can have a wide range of wavelengths and energy levels. Molecules that absorb specific wavelengths in the visible range of the spectrum are called pigments. Figure The . | Photosynthesis: Energy from Sunlight 8 Photosynthesis: Energy from Sunlight What Is Photosynthesis? How Does Photosynthesis Convert Light Energy into Chemical Energy? How Is Chemical Energy Used to Synthesize Carbohydrates? How Do Plants Adapt to the Inefficiencies of Photosynthesis? How Is Photosynthesis Connected to Other Metabolic Pathways in Plants? What Is Photosynthesis? Photosynthesis: “synthesis from light” The broad outline: Plants take in CO2 and release water and O2 Light is required Figure The Ingredients for Photosynthesis What Is Photosynthesis? Ruben and Kamen determined the source of O2 released during photosynthesis by using radioisotope tracers. Figure Water Is the Source of the Oxygen Produced by Photosynthesis What Is Photosynthesis? Two pathways: Light reactions: light energy converted to chemical energy (in ATP and NADPH + H+) Light-independent reactions: use the ATP and NADPH + H+ plus CO2 to produce sugars Figure An .
