Question

Can cellular respiration (a metabolic activity in a plant) occur if a plant was placed in the darkness for several days??

Answer 1

Think about what the general equation is for cellular respiration. The combination of sugar (glucose) and oxygen gives you carbon dioxide, water, and energy. Would being placed in a dark environment have any effect on that process?

Answer 2

No, I guess not. But does cellular respiration have anything to do with photosynthesis? Because if the plant was put in darkness then photosynthesis would not be able to occur?

Answer 3

Cellular respiration and photosynthesis are usually thought of as opposite processes within a cycle. If you take the cellular respiration equation from above and reverse it, you have the equation for photosynthesis, with one important difference. In cellular respiration, energy is released as a product (hence why we eat food for energy) whereas in photosynthesis it is needed as a reactant and must somehow be supplied for the reaction to proceed; this energy is provided via sunlight. Thus, you are correct; if you were to put a plant into darkness, no photosynthesis would occur due to the lack of energy provided by sunlight!

Answer 4

It would be able to work for a while, but the ATP provided from photosynthesis is necessary for cellular respiration, and since photosynthesis can't happen in the dark, respiration would soon stop.

Answer 5

Elly, while you are correct about ATP being required for cellular respiration (2 ATP must be input during glycolysis, known as the energy investment stage) the output is high enough (36-38 ATP) to sustain itself. The issue of being in the dark for a long amount of time would be the lack of sugar production in the Calvin cycle (due to the absence of photosynthesis). Without stored sugar, glycolysis could not occur and ATP would no longer be produced.

Answer 6

Okay thanks you guys! You really helped me out! :)