Barfing: The Enzymes in My Puke Ever wonder what's in your barf? It basically contains anything not digested from your last meal. Besides the recognizable stuff, there's the clear, slimy gastric mucus. This is mixed with a dab of slippery saliva. The glands dump mucus into your stomach to protect the walls from being eaten away by acids. Before you throw up, the walls of the stomach are irritated, so even more mucus oozes than usual. Also in this puke are enzymes that eat up butter fat, meat, eggs, starches and most of the things that you eat! (If you don't have an enzyme for something you eat, it ends up in your poop.) Why is the barf green? That comes from something called bile that is secreted by the liver into the small intestine which, when the food enters, looks like a soupy mixture called chyme.
Enzymes in Action: "Peptidize" Me
Introduction:
Even chemical reactions that release energy do not always occur
spontaneously and need some energy to get the reaction started. This is known as
activation energy. Many of the metabolic (chemical) reactions that occur within cells are too slow or have activation energies that are too high to make them practical in living tissues. Catalysts make these reactions possible by lowering the activation energy. Enzymes are usually proteins that act as biological (organic) catalysts. In this exercise we will learn how enzymes work using an enzyme known as peptidase, which helps digest the proteins that you eat. Two words you need to know are:
Hydrolysis:
Dehydration Synthesis:
Materials: models of peptidase, alanine, glycine, water, arrow
Procedure:
1. Cut out the water molecule and arrows on the following page.
2. What are alanine and glycine examples of?
3. What is peptidase?
4. Why is it named "peptidase?
5. Using your models, show a dehydration reaction. Be sure to show the intermediate step involving the enzyme-substrate complex. Identify the following:
