Question

In the plasma, Fe₂⁺ is oxidized to Fe₃⁺ by ferroxidase enzymes (e.g. hephaestin, ceruloplasmin) and requires Copper. What is the role of Copper in this process?

1) Copper acts as a catalyst in the oxidation reaction
2) Copper provides electrons for the oxidation reaction
3) Copper stabilizes the Fe₃⁺ ion
4) Copper prevents the formation of Fe₂⁺ ions

Answer 1

Copper acts as a catalyst in the oxidation of Fe²⁺ to Fe³⁺ by enabling rapid electron transfer through maintaining similar structures of oxidized and reduced forms of metal complexes, which is crucial for the activity of ferroxidase enzymes.

Step-by-step explanation:

The role of copper in the oxidation of Fe²⁺ to Fe³⁺ in the plasma, through the activity of ferroxidase enzymes such as hephaestin and ceruloplasmin, is primarily as a catalyst. Copper is a component of these plasma proteins and is essential for their function. Copper does not provide electrons for the oxidation reaction; rather, it is involved in stabilizing the electron transfer process. The copper ions in the enzymes help maintain similar structures for the oxidized and reduced forms of the metal complex, enabling rapid electron transfer necessary for the oxidation of iron. This means that copper's role revolves around facilitating the process by ensuring efficient electron transfer rather than donating or accepting electrons itself or stabilizing Fe³⁺ ions specifically.