Question

Oxygen is transported in blood mainly as:

• A. Oxyhaemoglobin
• B. Dissolved oxygen
• C. Carbaminohaemoglobin
• D. Bicarbonate ions

Hint:

Each molecule of haemoglobin can bind to a maximum of four oxygen molecules. This binding is influenced by factors like \(pO_2\), \(pCO_2\), \(H^+\) concentration, and temperature.

Answer 1

The Correct Option is A

Step 1: Understanding the Concept:
Oxygen transport in humans involves two primary methods: binding to specialized respiratory pigments in red blood cells or dissolving directly into the blood plasma.

Step 2: Detailed Explanation:
Oxygen transport occurs in the following proportions:
1. As Oxyhaemoglobin: Approximately \(97\%\) of the oxygen is transported by Red Blood Cells (RBCs). Haemoglobin (\(Hb\)), the red-colored iron-containing pigment, binds with oxygen in a reversible manner to form oxyhaemoglobin (\(HbO_2\)).
2. In Dissolved State: The remaining \(3\%\) of oxygen is carried in a dissolved state through the blood plasma.
Note that options (C) and (D) are modes of transport for Carbon Dioxide (\(CO_2\)), where \(70\%\) is carried as bicarbonate and \(20-25\%\) as carbaminohaemoglobin.

Step 3: Final Answer:
The primary mode of oxygen transport is through the formation of oxyhaemoglobin.