It was about 50 minutes into another long, boring two-hourlecture by Dr. Foster. The tall, thin, grayhaired biochemistryprofessor was concluding a chapter on enzymes. The final topic wasenzyme inhibition. Sarah, an energetic and outgoing junior, wasdaydreaming about her upcoming weekend at home for a familyreunion. She was not really paying attention, but heard theprofessor going on and on about alcohol dehydrogenase. At last, Dr.Foster turned to the class and asked, âAny questions?â Sarah,hoping to side-track the professor, enthusiastically waved herhand. As soon as she received a nod from Dr. Foster, she began torecount a story that her grandfather had told her. âMy grandfathersaid that when he was a teenager, alcohols were used as antifreezein automobiles. A group of kids was hanging out in a friendâsgarage. One of them found two bottles of liquid that were markedâalcohol.â He talked everyone else into trying the alcohol. All ofthe kids became severely ill, but about half of the teens died frompoisoning. Someone later found out that one of the bottlescontained methanol and the other a mixture of ethanol and methanol.The kids who lived drank the mixture. Grandpa figured since I was achemistry major, Iâd know why half died and half didnât, but Ididnât know. Do you?â Although Sarah had planned to side-track theprofessor, her story played nicely into his lesson plan. After all,the incident was related to the current class topic of enzymes andenzyme inhibition. The clever professor began, âLet me remind allof you that the enzyme, alcohol dehydrogenase, catalyzes the firstoxidation step in the case of both ethanol and methanol. Methanolis a very common solvent that is quite toxic. I recall an articlefrom a few years ago that described the largest mass methanolpoisoning reported to date. It occurred in Nicaragua. Of theapproximately 800 poisonings, about 45 patients died and otherssuffered blindness (SEMP Biot #412, 2006). I seem to recall thatpoisoned patients received either ethanol or a drug calledFomepizole as an antidote. I think I have some homework that willhelp you to understand what happened in your grandfatherâs story.âQuestions 1. What are the products of methanol and ethanol. 2. Comeup with a possible hypothesis for why some of the teenagers in thegrandfatherâs story died and the others did not. 3. Come up with apossible hypothesis for the case that include the role of theenzyme alcohol dehydrogenase.
It was about 50 minutes into another long, boring two-hourlecture by Dr. Foster. The tall, thin, grayhaired biochemistryprofessor was concluding a chapter on enzymes. The final topic wasenzyme inhibition. Sarah, an energetic and outgoing junior, wasdaydreaming about her upcoming weekend at home for a familyreunion. She was not really paying attention, but heard theprofessor going on and on about alcohol dehydrogenase. At last, Dr.Foster turned to the class and asked, âAny questions?â Sarah,hoping to side-track the professor, enthusiastically waved herhand. As soon as she received a nod from Dr. Foster, she began torecount a story that her grandfather had told her. âMy grandfathersaid that when he was a teenager, alcohols were used as antifreezein automobiles. A group of kids was hanging out in a friendâsgarage. One of them found two bottles of liquid that were markedâalcohol.â He talked everyone else into trying the alcohol. All ofthe kids became severely ill, but about half of the teens died frompoisoning. Someone later found out that one of the bottlescontained methanol and the other a mixture of ethanol and methanol.The kids who lived drank the mixture. Grandpa figured since I was achemistry major, Iâd know why half died and half didnât, but Ididnât know. Do you?â Although Sarah had planned to side-track theprofessor, her story played nicely into his lesson plan. After all,the incident was related to the current class topic of enzymes andenzyme inhibition. The clever professor began, âLet me remind allof you that the enzyme, alcohol dehydrogenase, catalyzes the firstoxidation step in the case of both ethanol and methanol. Methanolis a very common solvent that is quite toxic. I recall an articlefrom a few years ago that described the largest mass methanolpoisoning reported to date. It occurred in Nicaragua. Of theapproximately 800 poisonings, about 45 patients died and otherssuffered blindness (SEMP Biot #412, 2006). I seem to recall thatpoisoned patients received either ethanol or a drug calledFomepizole as an antidote. I think I have some homework that willhelp you to understand what happened in your grandfatherâs story.âQuestions 1. What are the products of methanol and ethanol. 2. Comeup with a possible hypothesis for why some of the teenagers in thegrandfatherâs story died and the others did not. 3. Come up with apossible hypothesis for the case that include the role of theenzyme alcohol dehydrogenase.
