Explain the transport of oxygen in blood .

Explanation

Molecular oxygen is carried in blood in two ways : bound to haemoglobin within the red blood cells and dissolved in plasma . Oxygen is poorly soluble in water , so only 3% of the oxygen is transported in the dissolved form `97%` of oxygen binds with haemoglobin binds with `O_(2)` is regulated by the partial pressure of `O_(2)` . Each haemoglobin carries maximum of four molecules of oxygen . In the alveoli high `pO_(2)` , low `pCO_(2)` , low temperature and less `H^(+)` concentration , favours the formation of oxyhaemoglobin , whereas in the tissues low `pO_(2)` , high `pCO_(2)` , high `H^(+)` and high temperature favours the dissociation of oxygen from oxyhaemoglobin .
A sigmoid curve (S- shaped) is obtained when percentage saturation of haemoglobin with oxygen is plotted against `pO_(2)` . This curve is called oxygen haemoglobin dissociation curve . This S-shaped curve has a steep slope for `pO_(2)` values between 10 and 50 mm Hg and then flattens between 70 and 100 mm Hg . Under normal physiological conditions , every 100 mL of oxygenated blood can deliver about 5 mL of `O_(2)` to the tissues .