To test the hypothesis that a particular plant synthesizes storage lipids by using glyceraldehyde 3- phosphate (G3P) from photosynthesis, a researcher plans to use radiolabeled precursors to track the molecules through the biosynthetic pathway. Which of the following radiolabeled precursors is most appropriate for the researcher to use?
A. 15N-labeled N2, because atmospheric nitrogen is fixed to amino acids by photosynthesisB. 32P-labeled phosphate, because lipids are stored in plants as phospholipidsC. 14C-labeled CO2, because atmospheric carbon is fixed to carbohydrates by photosynthesisD. 35S-labeled methionine, because amino acids are incorporated into lipids during photosynthesis