Question

Which one of the following elements is an activator for both ribulose biphosphate carboxylase/oxygenase and phosphoenol pyruvate carboxylase in photosynthetic carbon fixation?

• A. $M{g}^{2+}$
• B. $Z{n}^{2+}$
• C. $M{n}^{2+}$
• D. $C{l}^{-}$ and $K^{+}$

Answer 1

Answer: (A)

$M{g}^{2+}$

In photosynthetic carbon fixation, magnesium ion $\left(M{g}^{2+}\right)$ is an activator for both ribulose bisphosphate carboxylase/oxygenase and phosphoenolpyruvate carboxylase enzymes. The magnesium ions help to maintain the pH and helps in the activation of enzymes.

So, the correct answer is option A.