Chlorophyll is formed from protochlorophyll in light. The protochlorophyll lacks two hydrogen atoms one each at ____ and ____ carbon of ____ ring.

Correct option is D

✅ (d) 7th, 8th, IV
· Protochlorophyll lacks two hydrogen atoms at the 7th and 8th carbons of the IV pyrrole ring.
· These hydrogens are added during the photoreduction of protochlorophyll to chlorophyll.
· This step is light-dependent and critical for chlorophyll biosynthesis.
❌ (a) 8th, 9th, IV
· Incorrect as the hydrogens are missing at 7th and 8th carbons, not at the 9th.
❌ (b) 7th, 8th, I
· The ring involved is IV, not I.
· Misidentification of the ring makes this option wrong.
❌ (c) 8th, 9th, I
· Both carbon positions and ring number are incorrect.