* Water: Comes from the soil and is absorbed by the plant's roots.
* Light: Comes from the sun, which is absorbed by the chlorophyll pigment within the chloroplasts of plant cells.
Let's break down why:
* Light-Dependent Reactions: This stage of photosynthesis requires light energy to convert light energy into chemical energy in the form of ATP (adenosine triphosphate) and NADPH (nicotinamide adenine dinucleotide phosphate).
* Water's Role: Water molecules are split by the light energy, releasing electrons that power the creation of ATP and NADPH. This process also releases oxygen as a byproduct.
* Chlorophyll's Role: Chlorophyll, a green pigment found in chloroplasts, is crucial for absorbing sunlight. The light energy is used to excite electrons within the chlorophyll molecule, initiating the electron transport chain that ultimately generates ATP and NADPH.
In summary, water is absorbed from the environment, and light is absorbed by the plant's chlorophyll pigment, both providing the necessary resources for the light-dependent reactions of photosynthesis.
