Final answer:
The cytochrome P450 enzyme involved in the microsomal ethanol oxidizing system (MEOS) is CYP2E1.
Step-by-step explanation:
The cytochrome P450 enzyme involved in the microsomal ethanol oxidizing system (MEOS) is CYP2E1.
The MEOS system is responsible for metabolizing about 10 to 20% of the total liver ethanol uptake in moderate drinkers.
During heavy drinking, the MEOS system becomes more active and metabolizes most of the excess ethanol ingested, clearing it faster from the body.