The mineral element present in a chlorophyll molecule is :

Key Points

Chlorophyll - 

• In plants, photosynthesis takes place in chloroplasts, which contain the pigment chlorophyll
• Chloroplast is distinguished from other plastids by their green color
• The color is due to the presence of two pigments, chlorophyll a and chlorophyll b
• The chlorophyll pigment of the chloroplasts is mainly concerned with photosynthesis
• It has light-harvesting centers where the sunlight is absorbed
• This energy is used in a multi-step enzymatic breakdown takes place to yield glucose

Chlorophyll structure -

• C hlorophyll has a ring structure made of 4 pyrrole molecules
• The 4 pyrroles together are known as porphyrin
• Chlorophyll is a cyclic tetrapyrrolic structure
• It consists of a head made up of porphyrin rings with a phytol chain
• Magnesium ions are present at the center of the porphyrin rings
• Magnesium and iron are the minerals required for chlorophyll biosynthesis

Hence, Magnesium is present in the centre of chlorophyll structure, so the correct option is option 3) 

Additional InformationRole of Iron in Plants - 

• play role in biosynthesis of chloroplasts
• involved in photosynthesis and respiration along with protein complexes in electron transport
• aids in nitrogen-fixing
• helps move oxygen through the plant system

Role of Molybdenum in Plants - 

• essential component in two enzymes that convert nitrate into nitrite and then into ammonia
• needed by symbiotic nitrogen fixing bacteria in legumes to fix atmospheric nitrogen
• to convert inorganic phosphorus into organic forms in the plant

Role of Manganese in Plants - 

• is an essential cofactor for the oxygen-evolving complex (OEC) of the photosynthetic machinery