Which indecules does hemoglobin readity combine?

Hemoglobin readily combines with oxygen (O₂) in the lungs, where oxygen concentration is high, allowing it to transport oxygen to tissues throughout the body. It can also bind to carbon dioxide (CO₂) and hydrogen ions (H⁺), facilitating the transport of carbon dioxide back to the lungs for exhalation. Additionally, hemoglobin can interact with carbon monoxide (CO), which can bind more tightly than oxygen, posing a risk of carbon monoxide poisoning.