Respiration / Photosynthesis

20 points! Due Friday March 16 in class.  Answers must be typed and edited. Any diagrams must be neat. Make sure your name and class/time are in the upper right hand corner of your paper. If you use more than one sheet, staple all sheets together.

1. Explain why a poison that inhibits an enzyme critical for the Calvin cycle will also inhibit the light reactions. (2 points)

2. Compare electron transport in the mitochondrion and the chloroplast by answering the following questions for each organelle (1 point each):

A. Where do the electrons come from?

B. What picks up the electrons at the end of the electron transport chains?

C. Where do the electrons and hydrogen ions end up at the end of the process?

3. What do plants use the glucose produced from photosynthesis for? (3 points) Think: is it just used for cellular respiration?

4. ¹⁸O is a radioactive isotope of oxygen. How could you use this isotope to answer the following question: Does the oxygen produced by photosynthesis come from carbon dioxide or from water? (2 points)

5. Imagine you are a carbon atom in a carbon dioxide molecule that is taken into a plant for photosynthesis. Carefully trace the flow of the carbon atom through photosynthesis and cellular respiration ending up with carbon dioxide as a waste product of cellular respiration. Try to show as many of the steps as possible(5 points!).

6. Imagine you are an electron in a water molecule inside of a chloroplast. Trace your journey through the light reactions and the Calvin Benson cycle and then through cellular respiration back to water again. (5 points!).

I suggest you answer questions 5 and 6 with diagrams rather than typing out your answers. Please make your diagrams neat.