Final answer:
Sunlight provides the energy that chlorophyll in plants uses to excite electrons, which are then transferred through a series of reactions to create ATP and NADPH. These molecules store energy that is used in the Calvin cycle to convert CO2 into glucose, effectively transforming solar energy into chemical energy stored in carbohydrates.
Step-by-step explanation:
The energy from sunlight plays a crucial role in photosynthesis by providing the energy needed to rearrange atoms and forge new chemical bonds. When chlorophyll, the green pigment in plants, absorbs sunlight, it causes electrons within the chlorophyll to become excited and reach higher energy levels. These high-energy electrons then travel along a series of carrier molecules in a process known as the electron transport chain. As they move and transfer energy, they enable the synthetization of ATP and NADPH, energy carrier molecules vital for the light-independent reactions, or the Calvin cycle.
The light-independent reactions use the energy stored in ATP and NADPH to fix carbon dioxide (CO2) from the atmosphere into sugars like glucose. This series of reactions builds complex carbohydrates out of simpler molecules, storing energy in the stable covalent bonds of sugar molecules, making it available for the plant's use or for the entire ecosystem when the plant is consumed by other organisms. The overall effect of photosynthesis is the transformation of solar energy into chemical energy in the form of carbohydrates, vital for sustaining life on Earth.