Question

3) Spontaneous oxidation of the heme-bound Fe(to Fe() is prevented in hemoglobin by
1. the symmetry of it's quaternary structure,
2. the four heme-protein covalent bonds
3. a highly-ordered water molecule within the heme pocket
4. the surrounding protein structure in each subunit​

Answer 1

Answer:

Spontaneous oxidation of the heme-bound Fe(to Fe() is prevented in hemoglobin by

1. the symmetry of it's quaternary structure,

2. the four heme-protein covalent bonds

3. a highly-ordered water molecule within the heme pocket

4. the surrounding protein structure in each subunit

Answer 2

Spontaneous oxidation of the heme-bound Fe(to Fe() is prevented in hemoglobin 4. the surrounding protein structure in each subunit​

Spontaneous oxidation occurs in haemoglobin in which iron is oxidised from ferrous to ferric state. This process is also known as autooxidation.

Autooxidation reaction is as follows-

$HbFe^{+2}O_{2}$ → $Hb^{+3} + O^{-} _{2}$

However, the surrounding protein present in each subunit prevents this reaction.

Haemoglobin has two pairs of different proteins as - alpha and beta chains of haemoglobin. Each subunit is bound to heme with a covalent bond. And so, the autooxidation is prevented.