Which nutrient is a key component of the chlorophyll molecule?

The correct answer is magnesium, which is indeed a key component of the chlorophyll molecule. Chlorophyll is the green pigment found in plants that plays a critical role in photosynthesis, allowing plants to capture light energy from the sun. The structure of chlorophyll includes a porphyrin ring, at the center of which is a magnesium ion. This magnesium ion is essential for the proper functioning of chlorophyll, as it helps to stabilize the molecular structure and facilitates the absorption of light energy.

In addition, magnesium is vital for numerous biochemical processes in plants, including the synthesis of DNA and RNA, and it acts as a co-factor for many enzymatic reactions. While nitrogen is also important for plant health and is a component of amino acids and proteins, it is not structurally present in chlorophyll itself. Calcium and iron play crucial roles in plant development and functioning, but they are not central components of the chlorophyll molecule as magnesium is.