In the presence of carbon monoxide, less oxygen is transported to the blood. Suggest why, in terms of bond strength and stability constants.

Point 1: Stability constant with CO is greater than with 02.Point 2: Bond with CO is stronger than with 02.Explanation: In haemoglobin a central Fe2+ ion in an octahedral complex compromising four dative covalent bonds from the nitrogen's in a porphyrin ring, and one from a nitrogen on one of the amino acids on the globin molecule, which is the protein part of the haemoglobin molecule. The sixth ligand in the complex is oxygen.Carbon monoxide is toxic because it binds to the central Fe2+ ion more strongly than oxygen and replaces it in the complex. This means that oxygen cannot be carried around the body, causing asphyxiation.Equation: basic ligand substitution equation to be written in class.