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Enzymes. What are Enzymes?. Enzymes are proteins that speed up chemical reactions . They cause change, so they are also called catalysts . Reactions can occur without enzymes, but they may take a really long time. Enzymes lower the amount of energy needed for the reaction to take place.
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What are Enzymes? • Enzymes are proteins that speed up chemical reactions. • They cause change, so they are also called catalysts. • Reactions can occur without enzymes, but they may take a really long time. Enzymes lower the amount of energy needed for the reaction to take place. • http://www.stolaf.edu/people/giannini/flashanimat/enzymes/prox-orien.swf
Enzyme Labeling 1. 2. 3.
What can enzymes do? • Some enzymes can break down substances into smaller parts. • Other enzymes can build substances that cells need.
There are thousands of enzymes! Why? • Each enzyme is specific for one substrate (the substance it binds to). • The enzyme and substrate fit together like a lock and a key. • When the substrate and enzyme bind, the enzyme actually changes its shape a little. http://www.stolaf.edu/people/giannini/flashanimat/enzymes/enzyme.swf
Enzymes are “green”! • Once an enzyme has finished with helping one reaction, it’s ready for another. • Enzymes are reusable. http://www.biotopics.co.uk/other/anenz.html
Do enzymes always work? • NO - There are two factors that can denature enzymes, or alter the enzyme’s shape and stop it from doing its job. They are: • Temperature http://www.biotopics.co.uk/other/andnat.html • pH http://www.phschool.com/science/biology_place/labbench/lab2/ph.html (Denatured enzyme) • http://www.biotopics.co.uk/other/aninac.html
Has the enzyme been destroyed? • “Denatured” does not mean the enzyme has been destroyed. It has simply lost its shape. • Enzymes can be “renatured.” If they are returned to normal conditions, they will regain function.
When do enzymes work best? • Enzymes work best at an optimal temperature and pH level specific for that enzyme. Not all enzymes function at the same temp. or pH. Amylase- enzyme in mouth Pepsin- enzyme in stomach Arginase- enzyme in intestines Which ones work at the same pH?
How do you know it’s an enzyme? What do all these enzyme names have in common?
More Enzyme Animations • http://www.teachertube.com/view_video.php?viewkey=1879aed110525c185ff3 • http://www.lew-port.com/10712041113402793/lib/10712041113402793/Animations/Enzyme_activity.html • http://highered.mcgraw-hill.com/sites/0072495855/student_view0/chapter2/animation__how_enzymes_work.html