Which mineral is a key component of hemoglobin and helps transport oxygen in red blood cells?

Which mineral is a key component of hemoglobin and helps transport oxygen in red blood cells?

• A. Iron
• B. Calcium
• C. Magnesium
• D. Potassium

Answer: (A)

Oxygen transport in blood hinges on iron. Hemoglobin in red blood cells carries oxygen by binding it to iron atoms within the heme groups. Each hemoglobin molecule has four heme groups, and each iron atom reversibly binds one oxygen molecule as blood passes through the lungs and then releases it in tissues that need it. That iron-centered binding is what makes iron the essential mineral for this function. The other minerals—calcium, magnesium, and potassium—support different bodily roles (bones and signaling, enzyme cofactors, and electrical balance, respectively) and aren’t part of hemoglobin’s oxygen-binding mechanism. So iron is the mineral that enables hemoglobin to carry and deliver oxygen.

Oxygen transport in blood hinges on iron. Hemoglobin in red blood cells carries oxygen by binding it to iron atoms within the heme groups. Each hemoglobin molecule has four heme groups, and each iron atom reversibly binds one oxygen molecule as blood passes through the lungs and then releases it in tissues that need it. That iron-centered binding is what makes iron the essential mineral for this function. The other minerals—calcium, magnesium, and potassium—support different bodily roles (bones and signaling, enzyme cofactors, and electrical balance, respectively) and aren’t part of hemoglobin’s oxygen-binding mechanism. So iron is the mineral that enables hemoglobin to carry and deliver oxygen.