The question I am having trouble with is:
Scientists originally were uncertain whether the oxygen gas produced during photosynthesis came from CO2, H2O, or from both. How could radioisotope tracers be used to settle that question?
Chemistry - DrBob222
6CO2 + 6H2O ==> C6H12O6 + 6O2
Make O in CO2 radioactive; see where the radioactive O is at the end.
Make O in H2O radioactive; see where the radioactive O is at the end.
I'm sorry DrBob, I still don't understand what I am supposed to do. I wrote out the equations, but when you say to make the certain elements reactive, I'm not sure what you mean. Thank you for helping me!
The idea is to use an isotope of O or make O radioactive and use that to produce CO2 or H2O (that is make O different so you can find it). Then (if you made O radioactive) measure the glucose and the O2 and see if the O2 is radioactive or if the glucose is radioactive. Let's say you make some radioactive O and use that to make CO2. Go through the process of photosynthesis, measure with a radioactive counter the glucose and the O2. If the O2 comes from the CO2, the O2 produced by photosynthesis will be radioactive. Repeat using H2O that has radioactive O incorporated in it. It's the same thing as hiding a radioactive pellet in your clothes. A person with a Geiger counter can wave a "counting wand" over your clothes and see where the radioactive pellet has been hidden.
No problem! I can help clarify the process for you. In order to use radioisotope tracers to investigate the origin of oxygen gas produced during photosynthesis, you need to incorporate a radioactive form of oxygen into either carbon dioxide (CO2) or water (H2O).
To make a certain element radioactive, scientists can replace one or more stable isotopes of the element with a radioactive isotope. In this case, to investigate the source of oxygen gas, you need to introduce a radioactive isotope of oxygen (O) into either CO2 or H2O.
For instance, if you choose to make the oxygen in CO2 radioactive, you would replace one or both stable oxygen isotopes (O-16 and O-18) in CO2 with a radioactive isotope of oxygen, such as O-17 or O-15. Similarly, if you choose to make the oxygen in H2O radioactive, you would replace one or both stable oxygen isotopes in water with a radioactive isotope of oxygen.
Once the radioactive isotope is incorporated into the starting materials (CO2 or H2O), you would then perform the photosynthesis reaction and allow the process to occur. After photosynthesis is complete, you can analyze the products, particularly the oxygen gas (O2) produced.
By detecting the presence of radioactivity in the resulting oxygen gas, you can determine whether the radioactive oxygen atoms originally came from CO2 or H2O. If the radioactivity is detected in the oxygen gas, it suggests that the radioactive oxygen originated from the starting material in which it was initially incorporated. This analysis can help settle the question of whether oxygen gas is produced from CO2, H2O, or both during photosynthesis.
I hope this explanation helps you understand the process of using radioisotope tracers to investigate the origin of oxygen gas in photosynthesis. Let me know if you have any further questions!