20. The light-dependent reactions are dependent upon light
because it is from the photons of light which hit the chlorophyll that energy
is provided to split water (and thus provide the hydrogen ions needed to make
glucose) and also provide the energized electrons needed to make ATP and NADPH.
The plant needs the light-dependent reactions to occur to transform
light energy to chemical energy which the plant is capable of storing (the ATP
& NADPH).
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Long & Slichter