MediumZoologyBreathing and Exchange of Gases
+4 / -1
What percentage of CO₂ is transported as bicarbonate ions (HCO₃⁻) in the blood?
A
About 7%
B
About 23%
C
About 70%
D
About 90%
Explanation
CO₂ is transported in blood in three ways: (1) dissolved in plasma ~7%; (2) as carbaminohaemoglobin (bound to haemoglobin protein) ~23%; (3) as bicarbonate ions (HCO₃⁻) ~70%. In RBCs, CO₂ + H₂O → H₂CO₃ (catalysed by carbonic anhydrase) → H⁺ + HCO₃⁻. Bicarbonate is exported to plasma in exchange for Cl⁻ (chloride shift/Hamburger shift).
Previous
Which muscle is the primary muscle of respiration?
NextThe chloride shift (Hamburger phenomenon) occurs because:
More from Breathing and Exchange of Gases
Medium
The figure given below shows a small part of human lung where exchange of gas takes place. In which
HardMatch the Following: (a) Asthma 1. Inflammation of nasal tract(b) Bronchitis 2. Spasm of tracheal mu
HardThe rate of breathing is primarily controlled by the concentration of:
MediumThe respiratory rhythm centre is located in the:
MediumThe enzyme required for the transport of CO2 as bicarbonate is:
MediumEvery 100 mL of deoxygenated blood delivers approximately ______ of CO2 to the alveoli.
Practice Zoology Exams
Full-length mock tests with detailed analytics, rank, and percentile.
Browse Exams