MadSci Network: Chemistry
Query:

Re: relationship of bugs on windshields and poached egg to pan

Date: Sun Sep 24 21:28:13 2000
Posted By: John Carlson, Medical student, MD/PhD (parasitology) , Tulane University, School of Medicine
Area of science: Chemistry
ID: 968135978.Ch
Message:

Dear Roger,

You are correct in thinking the connection between bug guts on your car and egg in your pan is protein. Specifically, the proteins are hydrophillic proteins.

When the insects are alive, they have a liquid body cavity containing hemolymph. Hemolymph is their version of blood. Both hemolymph and blood contain hydrophillic proteins. Hydrophillic proteins are proteins that dissolve in water. (If the proteins in blood became solid, they would clog up all of the blood vessels. This is analogous to what happens in heat stroke.)

Eggs, as you know, are full of proteins. In their natural "raw" state, those proteins are also dissolved in water. Egg proteins are also hydrophillic.

When hydrophillic proteins are cooked, two things happen. First, they become denatured. Protein denaturation simply means that the protein's shape is changed. Imagine a wire coat hanger. If it were a hydrophillic protein being cooked, it would untwist itself into a straight metal wire. Its special coat-hanger function would be ruined. In this case, the proteins also lose their special hydrophillic nature, and can no longer dissolve in water. Water can only dissolve hydrophillic proteins, and the cooked proteins are no longer hydrophillic.

Secondly, when you cook an egg in your pan, or a bug on your car, the water is boiled away. When all of the water is gone, the denatured proteins are left smashed into every tiny nook and cranny of your pan and car. This makes it very difficult to pry them loose with scrubbing.

What can help you scrub off the egg and bug guts? Soap! How does soap work? Soap is an emulsifier. Emulsifiers are chemicals that break up fats, and make them somewhat hydrophillic.

In eggs and bug guts, there is also some fat. When the proteins are getting smashed into every nook and cranny, there is some fat that gets smashed in there too. Using soap, the fat is broken up, which allows the clot of proteins to be washed away.

Of course there is fairly little fat in eggs. And some insects have more fat than others. So often times, it's going to take brute force to remove those cooked denatured proteins!

For more information on how proteins denature I recommend to you two other MAD Scientist essays. Jill Irvin, a food scientist, explains denaturation in a thorough, easy to understand essay. Alvan Hengge, a chemist, explains the molecular biology of denaturation, and gives some links to other websites with information on the process.


Thank you for your question, and good luck scrubbing!

John


Current Queue | Current Queue for Chemistry | Chemistry archives

Try the links in the MadSci Library for more information on Chemistry.



MadSci Home | Information | Search | Random Knowledge Generator | MadSci Archives | Mad Library | MAD Labs | MAD FAQs | Ask a ? | Join Us! | Help Support MadSci


MadSci Network, webadmin@www.madsci.org
© 1995-2000. All rights reserved.