What does carbon monoxide bind with when inhaled?

When carbon monoxide is inhaled, it primarily binds with hemoglobin in the blood. Hemoglobin is the protein in red blood cells responsible for transporting oxygen from the lungs to the rest of the body. Carbon monoxide competes with oxygen for binding sites on hemoglobin, forming carboxyhemoglobin. This binding is significantly stronger than the binding of oxygen, which reduces the blood's capacity to carry oxygen and can lead to asphyxiation and other serious health effects.

Understanding this interaction is crucial for emergency responders and fire investigators, as it highlights the dangers of carbon monoxide in fire situations, where incomplete combustion can produce this toxic gas. While myoglobin primarily binds oxygen in muscle tissues, and plasma proteins and red blood cells are components of the circulatory system without specific binding affinities for carbon monoxide, the primary and most critical interaction occurs with hemoglobin.