HARD
AS and A Level
IMPORTANT
Earn 100
In both mitochondria and chloroplasts, an energetic electron passes along a chain of carriers and the energy released is used to synthesise ATP by chemiosmosis. Suggest why the process occurring in mitochondria is known as oxidative phosphorylation, whereas in chloroplast it is photophosphorylation.
Important Questions on Photosynthesis
MEDIUM
AS and A Level
IMPORTANT
It is often said that photosynthesis converts carbon dioxide to oxygen. Is this correct? Explain.
HARD
AS and A Level
IMPORTANT
In separate experiments, an actively photosynthesising plant was supplied with one of two labelled reactants:
- water containing the 18O isotope of oxygen.
- carbon dioxide containing the 17O isotope of oxygen.
In which products of photosynthesis would these isotopes be found?
MEDIUM
AS and A Level
IMPORTANT
Explain why the Calvin cycle stops running when there is no light and the TP (triose phosphate) is used up.
HARD
AS and A Level
IMPORTANT
The following graph shows the effect on the levels of GP (glycerate 3-phosphate) and TP (triose phosphate) in a chloroplast when it is exposed to light, dark and then light again. Describe and explain these results.
MEDIUM
AS and A Level
IMPORTANT
Which stage of the photosynthesis is limited by light intensity? Explain.
MEDIUM
AS and A Level
IMPORTANT
Which stage of the photosynthesis is limited by temperature? Explain.
MEDIUM
AS and A Level
IMPORTANT
Which stage of the photosynthesis is limited by carbon dioxide concentration? Explain.
HARD
AS and A Level
IMPORTANT
Explain how the inner membrane system of a chloroplast make it well adapted for photosynthesis.
