Alcohol Metabolism & Physiology Flashcards

The microsomal ethanol oxidizing system (MEOS) primarily involves which enzyme?

Answer: Cytochrome P450 2E1 (CYP2E1)

CYP2E1, located in the endoplasmic reticulum, is the key enzyme of the MEOS pathway and becomes increasingly important at high alcohol concentrations.

Henry's Law, as applied to breath alcohol testing, states that at a given temperature:

Answer: The amount of alcohol dissolved in a liquid is proportional to the partial pressure of alcohol above it

Henry's Law establishes that vapor pressure of a volatile substance in equilibrium with a solution is proportional to its concentration in that solution.

A 1°C increase in body temperature above 37°C is estimated to change the breath alcohol reading by approximately:

Answer: Increase by 6-7%

Each 1°C rise in body temperature increases alcohol vapor pressure and thus breath alcohol readings by approximately 6-7%, potentially overestimating true BAC.

Which of the following conditions can cause endogenous production of mouth alcohol that may interfere with a breath test?

Answer: Gastroesophageal reflux disease (GERD) or belching

GERD or belching can bring stomach alcohol vapors into the mouth and upper airway, potentially elevating BrAC readings if testing is not delayed.

The standard observation period before conducting an evidential breath test is intended to ensure:

Answer: No mouth alcohol from regurgitation, belching, or oral alcohol sources is present

The 15-20 minute deprivation/observation period ensures that any mouth alcohol dissipates so that only deep-lung alveolar air is sampled.

Acetate, the final major metabolic product of alcohol oxidation, is primarily:

Answer: Released into the bloodstream and oxidized in peripheral tissues

Acetate is released from the liver into the bloodstream and taken up by muscle and other peripheral tissues where it is oxidized to CO2 and water via the TCA cycle.

Which hepatic factor most significantly limits the maximum rate of alcohol metabolism in a non-tolerant adult?

Answer: NAD+ availability (NADH/NAD+ ratio)

The regeneration of NAD+ from NADH is the rate-limiting step; as NADH accumulates, ADH activity slows, effectively capping the elimination rate.