The majority of carbon dioxide produced by our body cells is transported to the lungs -

Options

A. dissolved in the blood
B. as bicarbonates
C. as carbonates
D. attached to hemoglobin

Answer

To solve the question regarding the majority of carbon dioxide produced by body cells and its transport to the lungs, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding Carbon Dioxide Production**:
- Carbon dioxide (CO2) is a byproduct of cellular respiration, which occurs in body cells.

2. **Transport Mechanisms of CO2**:
- Once produced, CO2 diffuses from the tissues into the bloodstream.

3. **Forms of CO2 in Blood**:
- CO2 can be transported in three main forms:
- Dissolved in plasma
- Bound to hemoglobin (forming carbaminohemoglobin)
- Converted to bicarbonate ions (HCO3-) and hydrogen ions (H+)

4. **Dissolved CO2**:
- A small percentage of CO2 is simply dissolved in the blood plasma.

5. **Carbaminohemoglobin Formation**:
- Some CO2 binds to hemoglobin to form carbaminohemoglobin, but this is not the majority.

6. **Bicarbonate Formation**:
- The majority of CO2 is converted to bicarbonate ions in a reaction facilitated by the enzyme carbonic anhydrase. This process occurs primarily in red blood cells.

7. **Conclusion**:
- Since the question asks for the majority of carbon dioxide transported to the lungs, we conclude that it is predominantly in the form of bicarbonate ions.

### Final Answer:
The majority of carbon dioxide produced by our body cells is transported to the lungs as bicarbonate ions.

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