Question

The activator for enzymes RuBisCO and PEPcase is

• A. micronutrient
• B. macronutrient
• C. beneficial element
• D. trace element

Answer 1

The correct option is B

macronutrient

The correct option is B

Explanation of the correct option:

1. Macronutrients are usually present in plant tissues in large quantities (more than 10 mmol Kg ^-1 for the dry matter).
2. Macronutrients include carbon, hydrogen, oxygen, nitrogen, phosphorus, sulfur, potassium, calcium, and magnesium.
3. Mg^{2 +} is the activator of both ribulose bisphosphate carboxylase oxygenase and phosphoenol pyruvate carboxylase.
4. Both enzymes are essential for the photosynthetic carbon dioxide fixation.

Explanation of the incorrect option:

Option A:

1. Micronutrients, or trace elements, are needed in very less quantities (less than 10 mmole Kg ^-1 for the dry matter).
2. These include iron, manganese, copper, molybdenum, zinc, boron, chlorine, and nickel.
3. For example, Mo is an activator of nitrogenase during nitrogen metabolism.

Option C:

1. There are a few beneficial elements such as sodium, silicon, cobalt, and selenium.
2. They are required by higher vegetation.
3. These promote the growth of plants and are required by specific taxons.

Final answer: The activator for enzymes RuBisCO and PEPcase is a macronutrient.