Photosynthesis In Higher Plants Question 61
Question: Cyclic and non-cyclic electron flow is used in plants to:
Options:
A) Meet the $\mathrm{ATP}$ demands of the Calvin Benson cycle.
B) Avoid producing excess $ \mathrm{NADPH+{H^{+}}} $ .
C) Balance $\mathrm{ATP}$ and $ \mathrm{NADPH+{K^{+}}} $ ratios in the chloroplast.
D) AIl of the above
Show Answer
Answer:
Correct Answer: D
Solution:
[d] $\mathrm{ATP}$ is required at higher levels in the Calvin-Benson cycle than $\mathrm{ NADPH+{H^{+}}}$.
Therefore, there must be a mechanism for producing additional $\mathrm{ATP}$.
Cyclic electron flow provides that mechanism.
If non cyclic electron flow were to be speed up to meet $\mathrm{ATP}$ needs, an excess of $ \mathrm{NADPH+{H^{+}}}$ would result.
Shifting between cyclic and noncyclic flow balances $\mathrm{ATP/NADPH + H^+}$ ratios.
BETA
