Alcohol Metabolism & Physiology Flashcards

Which enzyme is primarily responsible for converting acetaldehyde to acetate during alcohol metabolism?

Answer: Aldehyde dehydrogenase

Aldehyde dehydrogenase (ALDH) converts the toxic intermediate acetaldehyde into acetate in the second step of alcohol metabolism.

In the context of breath alcohol testing, the 'partition ratio' refers to the ratio of alcohol concentration in:

Answer: Alveolar air to arterial blood

The partition ratio (2100:1) describes how alcohol distributes between alveolar air and arterial blood at body temperature.

A subject has a BrAC of 0.080 g/210L. Applying the standard 2100:1 partition ratio, the estimated blood alcohol concentration (BAC) would be approximately:

Answer: 0.080 g/dL

Because the 2100:1 ratio is already built into breath test instruments, the BrAC reading is reported directly equivalent to BAC in g/dL.

Which body compartment has the highest water content, making it the primary distribution space for alcohol?

Answer: Total body water

Alcohol is hydrophilic and distributes throughout total body water, which represents about 60% of body weight in males.

What physiological factor explains why women generally reach higher BAC levels than men when consuming the same amount of alcohol per kilogram of body weight?

Answer: Women have a lower proportion of total body water

Women have proportionally less total body water than men, so the same dose of alcohol is distributed in a smaller aqueous volume, yielding a higher concentration.

The Widmark formula uses the variable 'r' to account for:

Answer: Individual body water distribution factor

The Widmark 'r' factor (also called the volume of distribution or Widmark factor) represents the fraction of body weight that is water available for alcohol distribution.

During the post-absorptive phase, blood alcohol concentration typically changes at a rate consistent with:

Answer: Zero-order kinetics

At typical drinking BAC levels, alcohol elimination follows zero-order kinetics, meaning a constant amount (not percentage) is eliminated per unit time.