Bioinorganic Chemistry Finding Metals in Living Systems

Bioinorganic Chemistry Finding Metals in Living Systems 

Photosynthesis is a chemical reaction that converts sunlight into energy for living organisms. It s one of the most remarkable reduction-oxidation reactions scientists have observed (see Chapter 3 for details on this type of reaction). There are two currently known systems of photosynthesis Photosystem I (PSI) and Photosystem 11 (PSll). They each use the light in a series of reactions that pass on electrons. The essential difference is that PSI creates hydrogen sulfide (H2S) by reduction of CO2 and is only conducted by anaerobic bacteria and was more common in prehistoric times. 

The PSII system will be the main focus because it s more important to the way that humans live and breathe. The PSll system creates oxygen gas (O2) by reduction of carbon dioxide (COj) and is conducted by all green plants and algae. 

During photosynthesis a molecule of carbon dioxide (CO2) is reduced, and a molecule of water (H2O) is oxidized. (See Chapter 3 for details on reduction-oxidation chemistry.) The result of these reactions is the production of dioxygen (O2) gas and a complex glucose, or sugar molecule, as illustrated in the following equation  

Photosynthesis in leafy green plants is carried out by a mol-eculesuch  

---

Chapter 17 Bioinorganic Chemistry Finding Metals in Living Systems 269... 

---