VKC ScienceChemistry for written exams Telegram

Indian Forest Service (Mains)

Chemistry optional

  • 2 papers
  • 200 marks each
  • 3 h per paper

Paper I covers physical and inorganic chemistry.

Indian Forest Service (Mains), Chemistry optional · 2023 · Paper I

Q5(b). Haem, chlorophyll and fluorescence

Question

State the structural differences between the macrocyclic rings present in chlorophyll and hemoglobin. How does the light-emitting behaviour of the macrocyclic ring present in chlorophyll change without and with metal ion in the cavity? Why does the change occur?

Answer in brief

Haem uses an Fe–porphyrin; chlorophyll uses an Mg–chlorin with a reduced pyrrole ring and an additional fused ring. Mg coordination changes the macrocycle's fluorescence spectrum and efficiency.

Part of VKC Basic

Read the key points and the full model answer with VKC Basic

VKC Basic (₹999 for 6 months) opens every solved answer, the notes, the handbook and the daily answer archive. Every Mains test series includes it.

See what is included Already a member? Sign in

The full model answer

As written for the answer booklet: the diagram carries the working, the lines stay short. Read here only; it is not offered as a download.

The handwritten model answer pages open with the VKC plan.
Read the whole 2023 solution2023 question paper

Topic notes: bio-inorganic chemistry (haemoglobin, cytochromes, Fe–S proteins, ion pumps), with every Civil Services, IFoS and Geo-Scientist PYQ →

Coverschlorophyllhaemporphyrin vs chlorinpheophytinfluorescencehemoglobin

All parts of Question 5