Question

The essential element that activates enzymes RuBisCO and PEPcase, also

• A. helps in carbohydrate translocation
• B. is essential for water splitting reactions
• C. forms constituents of phytol tail of chlorophyll
• D. is needed in the activity of pyruvic acid decarboxylase

Answer 1

The correct option is D is needed in the activity of pyruvic acid decarboxylase

Magnesium ions ($M{g^{2+}}^{}$) are required for RuBisCo, PEPcase and Pyruvic acid decarboxylase.
Boron plays a role in carbohydrate translocation in plants.
Manganese (${{\mathrm{Mn}}^{2+}}^{}$) is essential for water splitting reaction.
${{\mathrm{Mg}}^{2+}}^{}$ is the central metal ion in chlorophyll molecule too but it is not the constituent of the phytol tail.
It is required in activity of pyruvic acid decarboxylase. Pyruvate decarboxylase catalyses the decarboxylation of pyruvic acid to acetaldehyde and carbon dioxide.
RuBisCo and PEPcase are carbon-dioxide fixing enzymes. In C3 cycle. RuBisCo plays the role of fixing carbon dioxide to RuBp. In C4 cycle, PEP carboxylase fixes carbon dioxide with Phosphoenol pyruvate in mesophyll cells.