What is the function of the heme copper active site of cytochrome c oxidase?

Cytochrome c oxidase, a membrane-bound enzyme in the respiratory chain of aerobic organisms, reduces oxygen to water. This process, which takes place at the binuclear metal center constituted by a heme a3 and a Cu ion, runs via several intermediate states with lifetimes in the micro- and millisecond range.

What is a oxygen reductase?

Heme–copper oxygen reductases (HCO) reduce O2 to water being the last enzymatic complexes of most aerobic respiratory chains. These enzymes promote energy conservation coupling the catalytic reaction to charge separation and charge translocation across the prokaryotic cytoplasmatic or mitochondrial membrane.

What is the role of cytochrome c oxidase in the electron transport chain?

Mammalian cytochrome c oxidase (COX) is the terminal complex (complex IV) of the electron transfer chain. It catalyzes the transfer of electrons from ferrocytochrome c to molecular oxygen, converting the latter to water. The protein complex has 13 different subunits with a total molecular weight of 204,000 daltons.

What are the six classes of enzymes?

Enzymes are classified into six categories according to the type of reaction catalyzed: Oxidoreductases, transferases, hydrolases, lyases, ligases, and isomerases.

Why is complex 4 Important?

Cytochrome c oxidase or complex IV, catalyzes the final step in mitochondrial electron transfer chain, and is regarded as one of the major regulation sites for oxidative phosphorylation. This enzyme is controlled by both nuclear and mitochondrial genomes.

Does oxygen bind to Cox?

A two-electron reduction initiates a conformational change that allows oxygen to bind at the active site to the partially-reduced enzyme. Four electrons bind to COX to fully reduce the enzyme.

Why is lactate dehydrogenase important?

Lactate dehydrogenase (also called lactic acid dehydrogenase, or LDH) is an enzyme found in almost all body tissues. It plays an important role in cellular respiration, the process by which glucose (sugar) from food is converted into usable energy for our cells.