info about photosynthesis
In the 1600s, Jan Van Helmont made a reasonable hypothesis. He gathered that, in order for a tree to grow and gain mass, it must obtain food from somewhere else. He carefully weighed a tree and the soil that the he wanted to plant the tree in. Time passed, and the tree grew. After five years, he reweighed the tree, which had grown quite large, and then…wait for it…he weighed the soil. To his surprise, the soil weighed basically the same amount every day. Jan concluded that the tree must have gained the nutrients from the water that he had added over the years.
Jan was partially correct: water, as well as carbon dioxide and light, are required for photosynthesis. About 100 years later, another Jan, Jan Ingen-Housz, demonstrated that plants, well actually, only the green parts like the stems and leaves, could manufacture oxygen by using the Sun’s light and not its heat. Furthermore, Jan #2 proposed the novel idea that plants used carbon dioxide (CO2) while producing oxygen (O2).1 Then, in 1881, Theodor Engelmann discovered that photosynthesis occurs in the chloroplast.
Until the 1930s, the O2 produced from photosynthesis was believed to originate from CO2. L.B. Niel, a graduate student at Stanford University at the time, hypothesized that the O2 produced during photosynthesis came from H2O rather than from CO2. It was all well and good to suggest something like that, but it was not an easy hypothesis to test. The key was that scientists had to be able to distinguish whether the O2 came from CO2or H2O. In 1941, two scientists named Samuel Ruben and Martin Kamen did just that and showed that the O2 released during photosynthesis came from H2O. How did they do it? We know; the suspense is killing you. They made use of isotopes, or chemical elements that have the same number of protons as the regular element, but a different number of neutrons. These two geniuses also discovered 14C, an isotope of carbon, which has since been extensively used to carbon date fossils and ancient artifacts.
Since then, photosynthesis has remained an active area of research. Overall, ten Nobel Prizes in Chemistry have been given for work related to photosynthesis. Robert Huber and colleagues won the Nobel Prize in 1988 for uncovering the structure of the photosynthetic center, a discovery that Robert Huber describes as "switching on the light" of photosynthesis.6Discovering the structure of the photosynthetic machinery gave scientists better insight into how these photosynthetic reactions were actually occurring.
when water and light enter the cell
it goes through the calvin cycle
the Calvin cycle ends and O2 is released as a bypruduct