Identfy the incorrect statement

Options

A. Every 100 ml of deoxygenated blood delivers approximately 4 ml of `CO_(2)` to the alveoli
B. Carbonic anhydrase in present in very high concentration in RBC
C. High `pCO_(2)` and low `pO_(2)` in tissues help in binding of carbon dioxide with haemoglobin
D. `CO_(2)` is carries in haemoglobin as carboxyhaemoglobin

Answer

To identify the incorrect statement regarding the transport of carbon dioxide in the blood, we will analyze each statement provided in the question step by step.

### Step-by-Step Solution:

1. **Statement Analysis**: The first statement claims that "Every 100 ml of deoxygenated blood delivers approximately 4 ml of CO2 to the alveoli."
- **Evaluation**: This statement is generally correct. Deoxygenated blood does carry CO2 from the tissues to the alveoli for exhalation.

2. **Carbonic Anhydrase Presence**: The second statement mentions that "Carbonic anhydrase is present in very high concentration in RBC."
- **Evaluation**: This statement is also correct. Carbonic anhydrase is indeed found in high concentrations in red blood cells (RBCs) and plays a crucial role in converting CO2 to bicarbonate.

3. **Binding of CO2 with Hemoglobin**: The third statement discusses that "High pCO2 and low pO2 in tissues help in binding of carbon dioxide with hemoglobin."
- **Evaluation**: This statement is correct as well. High levels of CO2 (pCO2) in tissues promote the binding of CO2 to hemoglobin, while low levels of oxygen (pO2) facilitate this process.

4. **Carriage of CO2 in Hemoglobin**: The last statement claims that "CO2 is carried in hemoglobin as carboxyhemoglobin."
- **Evaluation**: This statement is incorrect. CO2 binds to hemoglobin to form carbaminohemoglobin, not carboxyhemoglobin. Carboxyhemoglobin refers to the compound formed when carbon monoxide (CO) binds to hemoglobin.

### Conclusion:
The incorrect statement is the last one: "CO2 is carried in hemoglobin as carboxyhemoglobin." The correct term for the compound formed when CO2 binds to hemoglobin is carbaminohemoglobin.

### Final Answer:
The answer to the question is option 4, which states that CO2 is carried in hemoglobin as carboxyhemoglobin.

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