This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Biochemistry
Which of the propeies accounts for ethanol's use in ethylene glycol poisoning? 
Select and explain. 
A. Competitive inhibitor of NADPH oxidase, B. Competitive inhibitor of alcohol dehydrogenase, C. Competitive inhibitor of aldehyde dehydrogenase, D. Non-competitive inhibitor of aldehyde dehydrogenase
B: Competitive inhibitor of alcohol dehydrogenase
Answer: B: Competitive inhibitor of alcohol dehydrogenase 
Explanation: Ethanol acts by competing with ethylene glycol for alcohol dehydrogenase, the first enzyme in the degradation pathway. Because ethanol has a much higher affinity for alcohol dehydrogenase, about a 100-times greater affinity, it successfully blocks the breakdown of ethylene glycol into glycoaldehyde, which prevents the fuher degradation. Ref: Lehninger Principles of Biochemistry, 4th Edition, Page 336; Updates in Emergency Medicine By John Cahill, 2002, Page 115