Which mineral is essential for making chlorophyll?

• A. Magnesium
• B. Iron
• C. Calcium
• D. Potassium

Answer: (A)

Magnesium is the mineral essential for making chlorophyll because it sits at the center of the chlorophyll molecule. That magnesium ion helps hold the chlorophyll’s ring structure in the right shape and enables the molecule to absorb light effectively for photosynthesis. Plants take up magnesium from the soil and use it directly to build chlorophyll; when magnesium is scarce, chlorophyll synthesis slows and leaves can yellow, signaling deficiency.

Iron is important for other parts of the photosynthetic machinery, like electron transport components, but it isn’t the central atom in chlorophyll. Calcium and potassium have important roles in plant cells as well, such as signaling and maintaining structure, but they do not form the chlorophyll core.