Question

Which element is located at the centre of the porphyrin ring in chlorophyll ?

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

Answer 1

Answer: (B)

Chlorophyll is the green pigment present in plants and some photosynthetic bacteria. The empirical formula of chlorophyll-a molecule is C₅₅H₇₂O₅N₄Mg. It consist of a porphyrin head and a phytol tail. Porphyrin is a cyclic tetrapyrrole structure, having a magnesium atom in the centre. Tail is consisted of phytol alcohol and it is attached with one of the pyrrole rings. The chlorophyll has empirical formula of C₅₅H₇₂O₅N₄Mg. It's molecular structure is comparable with chlorophyll-a.