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Cytochrome c oxidase catalyzes the reaction that reduces molecular oxygen (two oxygen atoms) to two water molecules. The electrons are added sequentially, and during the process cytochrome c oxidase must bind the oxygen tightly in the active site. Why?

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Final answer:

Cytochrome c oxidase requires tight binding of oxygen in the active site to ensure sequential addition of electrons, thus preventing the formation of reactive oxygen species and maintaining the efficiency of the electron transport chain and ATP production during aerobic respiration.

Step-by-step explanation:

Cytochrome c oxidase catalyzes the reduction of molecular oxygen to two water molecules in the electron transport chain. This enzyme is also known as Complex IV, which is part of the oxidative phosphorylation process during aerobic respiration. The enzyme needs to bind the oxygen molecule tightly because it transfers electrons to the oxygen one at a time, thus preventing the formation of harmful reactive oxygen species.

Complex IV, composed of cytochrome proteins c, a, and a3, holds an oxygen molecule very tightly between the iron of the heme group and copper ions until it is fully reduced to two molecules of water. This process is crucial for maintaining the efficiency of the electron transport chain and chemiosmosis, which is the primary method of ATP production in cells during aerobic respiration.

Tight binding of oxygen ensures that the electrons complete the reduction process effectively, thereby forming water and supporting the creation of a proton gradient that drives ATP synthesis. The mechanism also illustrates the specificity of the active site and the dynamic nature of enzyme-substrate interactions in biochemical processes.

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