I just came across a really cute story to demonstrate how catalysts and enzymes work.
The “Cattle-ist” Story
Farmer Bob has 23 cows. He also has 3 sons: Billy Bob, Joe Bob and Bubba.
One day, poor farmer Bob learns that he has pancreatic cancer and is told by the doctor that he should get his affairs in order. Bob goes to see his lawyer.
“When I am gone,” Bob says, “I want Billy to have 1/2 my herd. He’s the oldest and most ready to take on the challenges of farming. Joe Bob can have 1/3 of the herd, along with some land to get him started. And Bubba… well, he’s too young to deal with the responsibilities of managing his won farm. However, I’ll leave him 1/8 of my herd.”
Soon after, Bob passes away and his sons begin squabbling. They cannot determine a way to evenly divide the herd of 23 cows by 1/2, 1/3 and 1/8. Everyone wants whole cows. A neighbor, knowing what is happening to the family, decides to help. “Here,” she says, “I’m going to give you boys a cow so that you can peacefully settle your father’s estate.
Now there are 24 cows.
Billy Bob gets his half of the herd, which is 12 cows. Joe Bob is able to take his 8 cows (1/3 of the herd) and Bubba his 3 (1/8 of the herd). Since 12 + 8 + 3 = 23, the boys have finally divided the original herd by 1/2, 1/3, and 1/8 – and the neighbor can have her cow back.
How does this story represent the actions performed by catalysts and biological enzymes?
Answer (highlight to see): The neighbor’s cow is a catalyst, speeding up the reaction (dividing the cows). Notice that the neighbor’s cow is not used up in the process.