Photosynthesis and Respiration???

Question

How would you demonstrated that Elodea (a plant) carries out photosynthesis at a faster rate than it carries out respiration???

I was confused bc i thought that photosynthesis was respiration in plants... and then i thought if you put elodea in btb and put it in light and see how long it would take to turn yellow that would represent photosynthesis??? But what about respiration???

Answer 1

You need two identical plants and two identical chambers large enough to seal the plants into. One chamber can exchange air but gets no light. The other gets light but cannot exchange air. The plant that dies first had the most rapidly operating system shut down.

Answer 2

Im a freshmen, but Im at the end of my honors lab biology course and have gone through this subject. Photosynthesis and respiration both release ATP at the end of their cycle (energy). Also, they both are considered factors in determining whether something is biotic or abiotic. Differences: Photosynthesis only produces 2 ATP and Respiration produces much more (I think 48, but might need to double-check that). Photosynthesis is used only by plant cells and respiration is used by animal cells. Photosynthesis has the by-product of oxygen while respiration has the by-product of carbon dioxide.

Answer 3

Photosynthesis occurs in two steps.
1-photosynthetic step: In the first phase light-dependent reactions or photosynthetic reactions capture the energy of light and use it to make high-energy molecules (ATP and NADPH).
2- respiration step :In the second phase, the light-independent reactions use the high-energy molecules to capture carbon dioxide (CO2) and make the precursors of glucose, producing oxygen as a waste product.

You would simply have to show that with adequate light and water, there is a buildup of ATP and NADPH in the plant cells. It is logical, because the plant continues to use that molucule to produce glucose long after the sun goes down. In fact, if glucose is easier to measure than NADPH, just show that the plant continues to make glucose, and produce oxygen, in the dark. That would be proof enough.

Answer 4

Photosynthesis and respiation are opposites. Plants do both.
6CO2 + 6H2O-->C6H12O6 + 6O2 photosynthesis
C6H12O6 + 6O2-->6CO2 +6H2O respiration

You need to be able to measure the O2 given off by the Elodea to prove it makes more than it uses.