During yesterday's lecture, I started talking about how changes in temperature can cause a protein to change its shape and lose its function.
Then, for an every day example, I gave my students the example of a fried egg. Here's my quote:
"When you heat the egg, the protein changes shape, and the clear part becomes white. When you cool it back down, the egg stays white, so those proteins do not regain their function. They do however, retain their deliciousness."
I repeated that to a friend later in the day. He said it's a wonder that I don't have at least one student off him/herself every lecture.