Electrons are often removed from the electron transport chains to charge ferredoxin-NADP + reductase, the enzyme that reduces NADP +, releases the NADPH it makes into the stroma, right where it is needed for the dark reactions.
12.
Once that happens, the energy it took to achieve the transfer is stored in chemical form in the acceptor molecule and available for the final work of photosynthesis : the dark reactions, so named because they happen after light has been converted into energy.
13.
This process happens when light is available independent of the kind of photosynthesis ( C3 carbon fixation, C4 carbon fixation, and Crassulacean acid metabolism ); CAM plants store malic acid in their vacuoles every night and release it by day in order to make this process work . They are also known as dark reactions.
14.
Often plants will perform this second reaction ( called the " dark reaction " ) during the daytime, when the reactants made from the light reaction or readily available, although in climates where water is scarce they will often wait until after dark to prevent water loss . ~ Amory " ( c ) " 20 : 56, 16 October 2009 ( UTC)
15.
Like mitochondria, chloroplasts use the potential energy stored in an molecules between the photosystems harness the electrons'energy to pump hydrogen ions into the thylakoid space, creating a concentration gradient, with more hydrogen ions ( up to a thousand times as many ) Because chloroplast ATP synthase projects out into the stroma, the ATP is synthesized there, in position to be used in the dark reactions.
