Q7(a). Haemoglobin and cytochrome c; oxy- and deoxyhaemoglobin
Explain the common structural features of two major iron-containing proteins, haemoglobin and cytochrome c, present in the human body. Explain the coordination chemistry at the central metal atom in oxyhaemoglobin and deoxyhaemoglobin. Give the details of the spin states, magnetic moment and oxidation number of the central metal ion in both cases.
Answer in brief
Both are haem proteins with Fe held by four porphyrin N and a histidine N; deoxyhaemoglobin is five-coordinate high-spin Fe(II), 4.90 BM; oxyhaemoglobin is six-coordinate low-spin Fe(II), diamagnetic.
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Covershaemoglobincytochrome coxyhaemoglobindeoxyhaemoglobinspin statecooperativity
All parts of Question 7
- 7(a) Haemoglobin and cytochrome c; oxy- and deoxyhaemoglobin10 marks
- 7(b) Configurations of Pr, Eu and Gd and the moments of their M³⁺ ions10 marks
- 7(c) Rate expression for a bimolecular surface reaction10 marks
- 7(d) Electronic spectrum of [Ni(OS(CH₃)₂)₆]²⁺10 marks
- 7(e) Reversible isothermal expansion of an ideal gas10 marks