Question

A chronic alcoholic requires a much larger dose of ethanol as an antidote to methanol poisoning than does a nonalcoholic patient. Suggest a reason why a larger dose of the competitive inhibitor is required for an alcoholic.

Short answer

A larger dose of the competitive inhibitor is needed for a chronic alcoholic patient as the individual comprises greater amounts of alcohol dehydrogenase in the body.

Step-by-step solution

Chronic alcoholic

Chronic alcoholism constitutes a chromic disease comprising genetic and environmental factors impacting its development. Some signs of chromic alcoholism include craving alcohol and physical dependence.

Competitive inhibitor

Competitive inhibition happens when a substrate(S)and inhibitor(I) link to the same site of a particular enzyme. It creates a barrier on the active site and prohibits the substrate binding.

Reason why a larger dose of the competitive inhibitor is required for an alcoholic

A chronic alcoholic possesses a high amount of alcohol dehydrogenase in the body. Hence, a large amount of ethanol is needed to balance the alcohol (alcohol dehydrogenase). When intravenous alcohol is provided to the methanol poisoning patients , ethanol inhibits the enzyme ADH.

The reabsorption of water from urine does not occur in the absence of ADH. Hence, the urine is dilute and the amount of water content is greater in it.

So, ethanol forces the excretory system to produce more urine. The individual excretes more water than the net water consumption. Hence, it excretes most of the methanol with water before it gets oxidized into formic acid.

Hence, a larger dose of the competitive inhibitor is needed for a chronic alcoholic patient as the individual comprises greater amounts of alcohol dehydrogenase in the body.