How does haemoglobin transport oxygen

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The respiratory pigment in humans is Haemoglobin.It is a quaternary protein having 4 binding sites for oxygen. Hb has haeme protein with iron as a center. It has maximum binding capacity with Carbon-monoxide then with carbondioxide and lastly with oxygen.

Hb can combine with maximum 4 oxygen molecules and forms...

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The respiratory pigment in humans is Haemoglobin.It is a quaternary protein having 4 binding sites for oxygen. Hb has haeme protein with iron as a center. It has maximum binding capacity with Carbon-monoxide then with carbondioxide and lastly with oxygen.

Hb can combine with maximum 4 oxygen molecules and forms oxyhaemoglobin.100% saturation, is observed in rare cases. At maximum, 95% saturation is observed in blood. The maximum capacity of 1gram of haemoglobin to bind with O is 1.34ml.
From the alveoli, about 97% of oxygen can combine with haemoglobin. The binding of oxygen with Hb is termed as oxygenation. The factors responsible for oxygenation are:

1. High Partial pressure of Oxygen (pO 2).

2.Low concentration of Carbondioxide.

3.Neutral physiological pH.

4.Low temperature.

But, as the pO`_2` decreases, the binding of oxygen with Hb also decreases and free oxygen gets available to tissues for respiration.If we plot, oxygen -haemoglobin saturation with respect to partial pressure of oxygen, an S shaped oxygen dissociation curve is obtained.
Its been observed, about 5ml of oxygen per 100ml of blood passes into tissues.

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