Diary of a bad year

 This is an excerpt from the following book*1) as a memo of what I found interesting. Oxidation and reduction can proceed simultaneously in the same reaction field (on a photocatalyst), a characteristic unique to photocatalytic reactions that cannot be realized in other reaction systems.  When L-lysine, a kind of essential amino acid, is used as a raw material for photocatalytic reactions in aqueous solution in an oxygen-free atmosphere, pipecolic acid is generated. The photocatalytic synthesis of pipecolinic acid is the only synthetic pathway known to date that does not require any special reagents and does not produce any byproducts because the reaction involves redox reactions with excited electrons and holes.   The only photochemical reaction currently used for industrial production is probably the PNC method of ε-caprolactam synthesis by photo-nitrosation, developed by Toray Industries, Inc. ε-caprolactam is the raw material for 6-nylon, which is probably synthe...

 Let's consider the reaction from the plant to CO2 reduction based on the book*1). Before moving on to the reactions, the chloroplast of a plant is shown in the figure below. Photosynthesis consists of reactions that occur in thylakoids and reactions that occur in the stroma*2). Reactions occurring in thylakoids 　Chlorophyll in chloroplasts is activated by the absorption of light energy. From this absorbed energy, H2O is decomposed into [H]*3) and oxygen (O2), and the oxygen is discharged from the cell. The hydrogen H is divided into hydrogen ions H+ and electrons e-, and only the electrons are transferred between enzymes. In this process, ATP (adenosine triphosphate) is synthesized. The electron e-, which loses its energy, combines with the hydrogen ion H+ to form hydrogen [H], which is used in the rest of the reaction. 12H2O → 6O2 + 24[H] ④ Reactions occurring in the stroma (Calvin-Benson circuit) 　Carbon dioxide CO2 taken in from the outside is taken up by ribulose (pentose suga...