Question

Which of the following is a constituent of chlorophyll?

• A. Ni
• B. Mg
• C. Ca
• D. K

Hint:

Just as Iron (Fe) is the central atom in human hemoglobin, Magnesium (Mg) is the central atom in plant chlorophyll. This biological parallel makes it easy to remember.

Answer 1

The Correct Option is B

Step 1: Understanding the Concept:
Chlorophyll is the green pigment responsible for absorbing light energy during photosynthesis.
A central metallic ion is essential to stabilize the ring structure of this complex molecule.

Step 2: Detailed Explanation:
The molecular structure of chlorophyll consists of a porphyrin ring coordinated to a central metal atom.
This central atom is Magnesium (Mg), which occupies the core of the ring and is bonded to four nitrogen atoms.
Magnesium plays a crucial structural role, and its deficiency leads to a condition called chlorosis, where leaves lose their green color starting from older leaves.
Other options like Calcium (Ca), Potassium (K), and Nickel (Ni) have different physiological functions but do not form the core of the chlorophyll molecule.

Step 3: Final Answer:
Magnesium is the critical constituent of chlorophyll, corresponding to Option (B).