What substance is used to maintain iron in the Fe2+ state within the body?

Heme is a critical component in maintaining iron in the Fe2+ state within the body. Its structure includes a central iron atom that can exist in two oxidation states: Fe2+ (ferrous) and Fe3+ (ferric). In biological systems, Fe2+ is the active form that can easily bind to oxygen, which is essential for the function of hemoglobin and myoglobin in oxygen transport and storage.

Heme functions to stabilize iron in the ferrous state, allowing it to effectively bind oxygen during respiration. This stabilization is particularly important since iron can easily oxidize to Fe3+, at which point it would no longer have the capability to bind oxygen efficiently. By keeping iron in the Fe2+ state, heme ensures that proteins like hemoglobin, which carries oxygen in the bloodstream, and myoglobin, which stores oxygen in muscle tissues, can function optimally.

Other options, while related to iron metabolism or function, do not directly maintain iron in the Fe2+ state. Hemoglobin and myoglobin are oxygen-carrying proteins that contain heme, but they do not have an independent role in sustaining the ferrous state of iron. Ferroportin is a transport protein that aids in iron absorption and export from