Question

Protochlorophyll differs from chlorophyll in lacking

• A. 4 hydrogen atoms in two pyrrole rings
• B. 2 hydrogen atoms in one of its pyrrole rings
• C. 2 hydrogen atoms in two pyrrole rings
• D. 1 hydrogen atom in one pyrrole ring

Answer 1

The correct option is B 2 hydrogen atoms in one of its pyrrole rings

Photochlorophyll lacks two hydrogens at the 7 and 8 positions at the porphyrin part of the pyrrole ring. It is an oxidation product of chlorophyll a. In presence of light, it is reduced and esterified with phytol group to produce chlorophyll in presence of enzyme chlorophyllase.

So the correct option is '2 hydrogen atoms in one of its pyrrole rings'.