Question
In comparison to oxygen, what is the level of carbon monoxide’s affinity to hemoglobin?
| A. |
100
|
| B. |
400
|
| C. |
250
|
| D. |
150
|
Show Answer
|
Correct Answer � C
Explanation
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|
Carbon monoxide (CO) has an affinity for hemoglobin that is approximately 250 times greater than that of oxygen (O₂). This high affinity means that CO can easily bind to hemoglobin, forming carboxyhemoglobin, which reduces the hemoglobin’s ability to carry oxygen.
Key Points:
- Mechanism: When CO binds to hemoglobin, it reduces the availability of oxygen-binding sites. Additionally, it increases the affinity of hemoglobin for oxygen at other sites, which impairs oxygen release to tissues (leftward shift of the oxygen-hemoglobin dissociation curve).
- Clinical Impact: Even small concentrations of CO can lead to significant hypoxia because of its strong binding to hemoglobin.
