Daniel J. Arnon
In 1954 a Polish-born American Physiologist named Daniel J. Arnon took charge of an ambitious research effort that led to more informed insights into the process of photosynthesis. Arnon began to develop his agricultural knowledge at young age while growing up on a family farm. Arnon put his knowledge of plant nutrition to use when he served for the United States Army during World War II. The troops did not have access to arable land and this time, so Arnon grew and produced enough food to feed the troops using gravel and nutrient-enriched water. Following his service in the military, Arnon conducted research on chloroplasts and their vital role in photosynthesis. His research led to the discovery that energy from sunlight is utilized to add an additional phosphate to the already existing adenosine diphosphate to produce adenosine triphosphate. In addition to his discoveries, Arnon was the first scientist to reproduce the process of photosynthesis in a laboratory, in which he produced sugar and starch from carbon dioxide and water.
Robert Woodward
During the late 1940's an American organic chemist named Robert Woodward began synthesizing natural products of great complexity--quinine, cholesterol, cortisone, chlorophyll--creations that many of his colleagues believed to be unfeasible at this time. During the time that Woodward was working on the synthesis of these complex products, infrared spectroscopy was a newly developed technique that Woodward relied on heavily. It was in 1960 that Woodward successfully synthesized chlorophyll, and for his efforts he was awarded the Nobel Prize 5 years later in 1965.
Robert Hill and Fay Bendall
In addition to Robert Woodward's efforts in 1960, Robert (Robin) HIll and Fay Bendall proposed what is called the "z scheme" mechanism for photosynthetic light reactions. The significant behind this mechanism is that it proved that oxygen is created during the light requiring steps of photosynthesis. Just one year later in 1961, a scientist named Louis Duysens first proposed the concepts of photosystem I and photosystem II, and his research backed the findings of Hill and Bendall.