Answer: The answer is C. An iron atom located on the heme portion hemoglobin
Explanation: Hemoglobin is responsible for the transportation of oxygen in the red blood cells to tissues of vertebrates. It is the protein molecule found in the red blood cells.
Hemoglobin is made up of 4 heme molecules surrounding the globin group, forming a tetrahedral structure. The heme molecules contain one atom of iron each and this is the binding spot for each molecule of oxygen through a covalent bond. Therefore, each hemoglobin molecule can have up to four molecules of oxygen attached to them.
