23% amount of `CO_2` is transported in the blood as

Options

A. bicarbonate ions
B. carbaminohaemoglobin
C. carboxyhaemoglobin
D. carbonates

Answer

To solve the question regarding how 23% of CO2 is transported in the blood, we can break down the information step by step:

### Step-by-Step Solution:

1. **Understanding CO2 Transport in Blood**:
- The blood is responsible for transporting both oxygen (O2) and carbon dioxide (CO2).
- CO2 is transported in three main forms in the blood: as bicarbonate ions, bound to hemoglobin, and dissolved in plasma.

2. **Forms of CO2 Transport**:
- **Bicarbonate Ions**: Approximately 70% of CO2 is transported in the form of bicarbonate ions (HCO3-) after it reacts with water in the presence of carbonic anhydrase.
- **Carbaminohemoglobin**: About 20-25% of CO2 binds with hemoglobin to form carbaminohemoglobin.
- **Dissolved CO2**: Around 7% of CO2 is transported dissolved in the plasma.

3. **Identifying the Percentage**:
- The question specifies that 23% of CO2 is being asked about. This percentage falls within the range of 20-25% that is transported as carbaminohemoglobin.

4. **Conclusion**:
- Since 23% is approximately equal to the 20-25% range of CO2 transported as carbaminohemoglobin, we conclude that the answer to the question is **carbaminohemoglobin**.

### Final Answer:
The 23% amount of CO2 is transported in the blood as **carbaminohemoglobin**.