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Photosynthesis occurs in two sets of reactions that ..

What are two sets of reactions in photosynthesis? - Answers

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Photosynthesis has two main sets of reactions.

For each electron flowing from water to NADP+ (a net change in1.14 volts), two quanta of light are absorbed, one by eachPhotosystem. Each molecule of oxygen released involves the flowof four electrons from two water molecules to two NADP+s andrequires four quanta of sunlight absorbed by each Photosystem toprovide the energy to do this. These are the "Light PhaseReactions" of photosynthesis, which produce two high energychemical products, namely NADPH and ATP.

In photosynthesis there are two sets ..

The NADPH is the main in chloroplasts, providing a source of energetic electrons to other reactions. Its production leaves chlorophyll with a deficit of electrons (oxidized), which must be obtained from some other reducing agent. The excited electrons lost from chlorophyll in are replaced from the electron transport chain by . However, since includes the first steps of the Z-scheme, an external source of electrons is required to reduce its oxidized chlorophyll a molecules. The source of electrons in green-plant and cyanobacterial photosynthesis is water. Two water molecules are oxidized by four successive charge-separation reactions by photosystem II to yield a molecule of diatomic and four ions; the electron yielded in each step is transferred to a redox-active residue that then reduces the photoxidized paired-chlorophyll a species called P680 that serves as the primary (light-driven) electron donor in the photosystem II reaction center. The oxidation of water is in photosystem II by a redox-active structure that contains four ions and a calcium ion; this binds two water molecules and stores the four oxidizing equivalents that are required to drive the water-oxidizing reaction. Photosystem II is the only known biological that carries out this oxidation of water. The hydrogen ions contribute to the transmembrane chemiosmotic potential that leads to ATP synthesis. Oxygen is a waste product of light-dependent reactions, but the majority of organisms on Earth use oxygen for , including photosynthetic organisms.

The two major sets of reactions involved in photosynthesis are :

Carbon dioxide is converted into sugars in a process called . Carbon fixation is a reaction, so photosynthesis needs to supply both a source of energy to drive this process, and also the electrons needed to convert carbon dioxide into , which is a . In general outline, photosynthesis is the opposite of , where glucose and other compounds are oxidized to produce carbon dioxide, water, and release chemical energy. However, the two processes take place through a different sequence of chemical reactions and in different cellular compartments.

Although photosynthesis can happen in different ways in different species, some features are always the same. For example, the process always begins when energy from light is absorbed by called that contain . In plants, these proteins are held inside called , while in bacteria they are embedded in the . Some of the light energy gathered by chlorophylls is stored in the form of (ATP). The rest of the energy is used to remove from a substance such as water. These electrons are then used in the reactions that turn carbon dioxide into organic compounds. In plants, algae and cyanobacteria this is done by a sequence of reactions called the , but different sets of reactions are found in some bacteria, such as the in . Many photosynthetic organisms have that concentrate or store carbon dioxide. This helps reduce a wasteful process called that can consume part of the sugar produced during photosynthesis.

c shows that there are two sets of reaction in photosynthesis;

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  • Photosynthesis can be divided into two major sets of reactions ..

    so there must be two sets of reactions in the full process of carbon assimilation.

  • Essentially there are two sets of reactions.

    There are two component sets of reactions that occur sequentially: light reactions and dark reactions.

  • there were two photosystems, one ..

    The two major sets of reactions involved in photosynthesis are light reactions and ..

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