ENZYME Notes: Ch. 6

ENZYME Notes: Ch. 6 KEY WORDS/ NOTES QUESTIONS What are Enzymes? The top curve represents a reaction occurring on its own. “b” represents the Activation Energy or the Energy Available amount of energy required to Hook-up/Break- to hook molecules together, down molecules or to break molecules apart. Compare that peak to the one below it. The curve on the bottom represents how much energy it takes with an enzyme...significantly a.k.a. “TIME” less! So, reactions that contain enzymes, will tend to proceed faster b/c they don’t need as much energy. The only way to get the reactions to occur with out enzymes is to heat up the solution to a high enough temperature that the molecules will move fast and bump into each other. The problem with that, is the temperature requirement is to great for a living organism...we would die! Enzyme Structure Enzymes are examples of proteins. They form “blobs” b/c when they are being created in the cells, the amino acid chains need to clump together to conserve space. A critical part to this clumping is that they form grooves...ACTIVE SITES. If they don’t clump the right way, there is no properly formed ACTIVE SITE.

So what? The shape is so important! If the enzyme is not shaped the correct way, the active site groove can’t fit the substrate. So if the enzyme is AMYLASE, an important enzyme in saliva that helps to break down polysaccharides, we wouldn’t be able to get energy from eating foods high in starch. We couldn’t break the individual glucose molecules apart and use them to make energy for the body.

Other examples: 1. Liver releases bile to break down lipids 2. Pancreas releases pancreatic juices to help in digestion. 3. DNA is photocopied using enzymes...no DNA copy, no new cells when you fall and scrape your leg. 4. Enzymes remove oxygen from the hemoglobin so that it can get into your tissues. No enzyme, no oxygen, no working muscles, brains, hearts, etc! ENZYME Notes: Ch. 6 Destroying Enzyme To stop an enzyme from functioning/doing it’s job, you need to Function: change its shape. ENZYMES STOP WORKING WHEN CONDITIONS ARE NOT RIGHT. What are the “right conditions”? 1. Specific temperature ranges (The enzymes in your body work at what temp? The enzymes in bacteria that live in hot springs work at a much higher temperature.) 2. Specific pH ranges (The enzymes in your stomach work at what pH? What about the enzymes in your mouth?) 3. Specific substrates to fit into active sites

So...if you change any of these conditions, you will cause the enzyme to stop functioning...either temporarily or at other times permanently. Sometimes the enzyme breaks apart an unwinds back to primary structure: DENATURATION