Photosynthesis that a complex of reactions consisting of an intermediate to cytochrome b (now a plastoquinone), another is from cytochrome f to a step in the carbohydrate-generating mechanisms. These are linked by plastoquinone, which does require energy to reduce cytochrome f for it is a sufficient reductant. Further experiments to prove that the oxygen developed during the photosynthesis of green plants came from water, were performed by Hill in 1937 and 1939. He showed that isolated chloroplasts give off oxygen in the presence of unnatural reducing agents like iron oxalate, ferricyanide or benzoquinone after exposure to light. The Hill reaction is
Fractionation of carbon isotopes in oxygenic photosynthesis activity, and variations in cell growth and geometry. The isotopic fractionations of different photosynthetic pathways are uniquely characterized by these factors, as described below. A C3 plant uses C3 carbon fixation, one of the three metabolic photosynthesis pathways which also include C4 and CAM (described below). These plants are called "C3" due to the three-carbon compound (3-Phosphoglyceric acid, or 3-PGA) produced by the CO fixation mechanism in these plants. This C3 mechanism is the first step of the Calvin-Benson cycle, which converts CO and RuBP into 3-PGA. C3 plants are the most common type of plant, and typically thrive under