Question

Magnesium in chlorophyll molecule is located in

• A. Centre of porphyrin head
• B. Corner of porphyrin head
• C. Phytol tail
• D. None of the above.

Answer 1

The correct option is A Centre of porphyrin head

Photosynthesis takes place in the green leaves of plants and another green part of plants like stem etc. The most active photosynthetic tissue in higher plants is the mesophyll of leaves. Mesophyll cells have many chloroplasts, which contain the specialized light absorbing pigments. These pigments are known as photosynthetic pigments. Chlorophyll and carotenoids are the types of photosynthetic pigments. Chlorophyll is the primary pigment and carotenoids are the accessory pigments. Chemistry of photosynthetic pigments was first studied by Willstatter and Stoll in 1912. They discovered that chlorophyll has a tadpole-like configuration. It has a head called porphyrin and a tail made up of long chain alcohol called phytol. Porphyrin head is made up of four pyrrole rings which are linked by methine bridges. 5 atoms— 4 carbon and one nitrogen forms the skeleton of each pyrrole ring. Chlorophyll contains a Magnesium ion. Four nitrogen atoms surround and bind the Magnesium atom. Magnesium in chlorophyll molecule is located in centre of porphyrin head. This centre uniquely defines the structure as a Chlorophyll molecule.