One of the major questions in the early research of photosynthesis was the question of whether the oxygen that is produced originates from CO2 or H2O. Cornelius van Niel was an early proponent that H2O was the source of the oxygen. His work demonstrated that purple bacteria used hydrogen sulfide (H2S) in the presence of sunlight to produce carbon dioxide (CO2), water and sulfur, according to the equation: 6CO2 + 12H2S + light ⟶ C6H12O + 6 H2O +S2 The similarity between H2S and H2O lead van Niel to conclude that water was the donor for oxygen in the normal photosynthesis reaction. However, it was not until 1941 that Ruben and Kamen were able to demonstrate this experimentally. Read the short article: Ruben, S., M. Randall, M. D. Kamen, and J. L. Hyde. 1941.
Heavy oxygen (O18) as a tracer in the study of photosynthesis. Journal of the American Chemical Society 63(3): 877–879. In your own words, write a summary of the article that includes: 1) the question the authors were trying to answer; 2) the experimental design; 3) the results of the experiment; and 4) the conclusion the authors came to, based on their results. Your summary should be typed in Times New Roman 12-pt font and be one-and-a-half-spaced with 1” margins. It should be a minimum of 1 page and maximum of 2 pages.
The header block does not count towards the page limit. You may type directly into the window of the Assignments page or you may upload a .docx, .pdf or .gdoc document. Contact your TA for permission, if you plan to use any other format (e.g., Apple Pages). In addition, your TA may ask for a hard copy of this assignment to be turned in at the start of class. You will need to use properly cited references.
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