The difference between an enzyme and a hormone.

It is a classic from Dad's joke bank. We all know it. "Can you tell me what is the difference between an enzyme and a hormone?"

Admittedly, I have adopted it into my own, very limited, joke circulation.  The problem is that while Dad was able to bestow this gem upon unsuspecting college biology students I have a difficult time finding an audience who can truly appreciate the genius of the joke. Often, upon administering the joke I am met with blank stares and friends who politely divert the conversation in another direction. But finally, last night, I was able to deliver the joke it its full science nerd glory.

My friend Matt and I were huddled over some delicious Thai coconut basil mussels discussing various nerdy topics such as non-Newtonian fluids, how a zombie virus could actually exist and chronic alcoholism's effect on bone density when there came a lull in the conversation.  Cooley I said "Can you tell me the difference between an enzyme and a hormone?"

Being that Matt is a medical doctor he was more than happy to launch into an at-length explanation of the differences between the two biochemicals. As he moved from each chemicals production into function, I sat politely nodding away at his various statements. After a good five minutes of narration he stopped and asked if he had provided a thorough enough explanation.  "That was a really good explanation. But you are wrong." I replied. Immediately Matt's face took on the appearance of a child who had just been told that Santa doesn't exist. "Really?" he said. This was the moment I had been waiting for. Slowly, trying to control smile from  creeping across my face, I said "Yeah, don't you know that you can't hear an enzyme." Dumbfounded Matt stared back at me. Then he got it and laughter erupted.

Now this beautiful execution of Dad's classic joke would have been fantastic all on its own but it was made better by what Matt shared with me this morning. I had just arrived at work when I received a series of frantic texts from Matt. Apparently he was so tickled by my telling of the joke that he decided to try it out on his attending physician. Giddily Matt reported that at first his attending had rolled his eyes but that quickly the joke was being retold to other docs on the floor. So although Dad's joke can be difficult to retell among most social circles it lives on in the hearts of nerds everywhere.