2.7.3 Plants: Gas Exchange in Photosynthesis & Respiration Flashcards
The processes of respiration and photosynthesis both rely on what?
on the exchange of oxygen and carbon dioxide
respiration process requires, what?
the uptake of oxygen and the release of carbon dioxide
The oxygen diffuses down the concentration gradient from, what
a high concentration (outside the leaf) to a low concentration (inside the leaf)
- The cells use oxygen in respiration so the concentration is always low inside the respiring cells
The carbon dioxide diffuses down the concentration gradient from a, what?
high concentration (inside the leaf) to a low concentration (outside the leaf)
In respiration, carbon dioxide diffuses ** of the leaf and oxygen diffuses ** the leaf
In respiration, carbon dioxide diffuses out of the leaf and oxygen diffuses into the leaf
Plant cells photosynthesize when there is enough, what?
sunlight
Plants can only photosynthesize when they have access to, what?
light, however, cells respire all the time
- This means that gas exchange in plants varies throughout a 24 hour period
During the daytime plants both, do what?
respire and photosynthesize
The rate of photosynthesis tends to be higher than the rate of, what?
respiration (unless there is a low light intensity)
Therefore there is net diffusion of carbon dioxide into the plant and net diffusion of oxygen out of the plant during the day
During the nighttime, plants only, what?
respire
Because of a night plants only respire, this means that there is a net movement of what?
net movement of oxygen into the plant and net diffusion of carbon dioxide out of the plant during the night time
At low light intensities, the rate of photosynthesis is equal to, what?
the rate of respiration
This means that there is no net movement of oxygen or carbon dioxide in either direction
Chloroplasts are only found in the following leaf cells:
Palisade Mesophyll cells
Spongy Mesophyll Cells
Guard Cells (around stomata)
