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Breathing and Exchange of Gases

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CBSE Gujarat Board Haryana Board

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Class 10 Class 12

What are the major transport mechanisms for CO2
? Explain.

Transportation of carbon dioxide : It is transported in three forms :

1. In solution form : About 7% CO2 dissolves in plasma and is transported as such.

(2) Through RBCs: About 20 – 25% of CO2 is transported by the red blood cells as  carbaminohaemoglobin. Carbon dioxide binds to the amino groups on the polypeptide chains of haemoglobin and forms a compound known as carbaminohaemoglobin.

(3) Through sodium bicarbonate: About 70% of carbon dioxide is transported as sodium bicarbonate. As CO2 diffuses into the blood plasma, a large part of it combines with water to form carbonic acid in the presence of the enzyme carbonic anhydrase. Carbonic anhydrase is a zinc enzyme that speeds up the formation of carbonic acid. This carbonic acid dissociates into bicarbonate (HCO3) and hydrogen ions (H+).

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What is the partial pressure of oxygen in  oxygenated blood ?

95 mm Hg
702 Views

Oxygen is carried by haemoglobin as?

Oxyhaemoglobin.
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By what amount the solubility of carbondioxide is more than the solubility of oxygen?

20 - 25 times
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Name the cavity having lungs.

Thoracic cavity.
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70% of carbondioxide is transported as ?

Bicarbonate
360 Views