Which materials produce during the light reactions of photosynthesis are essential to the dark reactions?
Light Reactions (Occurs in Grana)
The purpose of the light reactions is to change light energy into chemical energy of ATP and NADPH.
a) Require light
b) Light makes excited electrons leave the chlorophyll. The electrons pass their energy to make ATP.
c) The light splits water to make hydrogen ions (H+) and oxygen.
d) The oxygen is released to the air.
e) The H+ and more excited electrons are used to make NADPH (an energy & H+ carrier).
ATP carries energy to the dark reactions.
Source:
http://ghs.gresham.k12.or.us/science/ps/sci/soph/energy/intbio/photo/rxns.htm
During the light reactions of photosynthesis, two important materials are produced that are essential to the dark reactions. These materials are ATP (adenosine triphosphate) and NADPH (nicotinamide adenine dinucleotide phosphate).
The light reactions occur in the grana (thylakoid membranes) of the chloroplasts and are the initial step in the process of photosynthesis. They require light and their main purpose is to convert light energy into chemical energy in the form of ATP and NADPH.
When light is absorbed by the chlorophyll molecules in the grana, it excites the electrons, causing them to leave the chlorophyll. These excited electrons pass their energy along an electron transport chain, resulting in the production of ATP through a process called photophosphorylation.
At the same time, the light also splits water molecules (H2O) into hydrogen ions (H+) and oxygen. The oxygen is then released into the air as a byproduct of photosynthesis.
The hydrogen ions (H+) and more excited electrons are used to reduce NADP+ (nicotinamide adenine dinucleotide phosphate) to form NADPH. NADPH acts as an energy carrier, as well as a carrier of hydrogen ions, which will be used in the dark reactions.
Therefore, ATP and NADPH are the products of the light reactions and they play a crucial role in providing energy and reducing power to the dark reactions (also known as the Calvin cycle or light-independent reactions). The dark reactions, which occur in the stroma of the chloroplasts, use the energy from ATP and the reducing power of NADPH to convert carbon dioxide (CO2) into glucose, a process known as carbon fixation.
In summary, the materials produced during the light reactions of photosynthesis that are essential to the dark reactions are ATP and NADPH.