ENZYMES

___________ HELP CHEMICAL REACTIONS _______________ HAPPEN FASTER Image from: Pearson Education Inc, publishing as Pearson Prentice Hall. All rights reserved CATALYSTS ___________ HELP CHEMICAL REACTIONS _______________ HAPPEN FASTER Catalysts work by ____________ the ___________________________to get a chemical reaction started. DECREASING ACTIVATION ENERGY required

CATALYSTS in Living Things Image from: http://www.hillstrath.on.ca/moffatt/bio3a/digestive/enzanim.htm CATALYSTS in Living Things In living systems __________ that ________________to control chemical reactions are called = _________ PROTEINS act as catalysts ENZYMES SEE ANIMATION of AMYLASE More about this in Chapters 7,8,9 and 12

Energy in Reactions *** Energy is released or absorbed whenever chemical bonds form or are broken *** Chemical reactions involve changes in energy Activation energy – energy needed to start a chemical reaction

Enzymes Some reactions are much too slow and need something to speed them up – that’s why we need enzymes Enzymes -proteins that speed up chemical reactions, or act as a catalyst Catalyst – substance that speeds up a chemical reaction with out being consumed by the reaction – therefore lowering the activation energy Most enzyme names end in –ase Very specific

How do enzymes work? enzymes Provide a site where reactants can be brought together to react. Reactants are called substrates Substrates bind to the enzymes “active site” like a puzzle and they remain together until the reaction is done. Involved in almost all metabolic processes. Ex. Speed up reactions in digestion of food, synthesis of molecules, and the storage and release of energy. enzymes Thinking question – have you ever heard the word enzyme? What was it referring to?

Enzymes are reuseable Enzymes can be used over and over again – they are not consumed by the reaction. Enzymes can be denatured (lose their shape) if they are exposed to high temperature or a change in pH. Enzymes in the body work at a pH of 7

Common enzymes Lactase – responsible for breaking down the lactose in dairy products – those that do not have it are “lactose intolerant”

______________ to get a chemical reaction _______________ = ________________________ Energy required STARTED ACTIVATION ENERGY ACTIVATION ENERGY REACTANTS PRODUCTS Image from: Pearson Education Inc, publishing as Pearson Prentice Hall. All rights reserved

PROTEINS CAN BE ENZYMES SUBSTRATE ENZYME-SUBSTRATE COMPLEX ENZYME Unchanged & Reusable PRODUCTS Image modified from: http://www.biologie.uni-hamburg.de/b-online/library/cat-removed/enzyme_.gif Arrow: http://www.gifanimations.com/action/ImageDisplay/1/2/11/next

Click HERE to learn more about enzymes ENZYMES _____ like a _______________ to only _________of _________. Enzymes are ___________ by the reaction and ___________ FIT LOCK AND KEY SUBSTRATE ONE KIND UNCHANGED REUSABLE http://www.grand-illusions.com/images/articles/toyshop/trick_lock/mainimage.jpg

FACTORS THAT AFFECT ENZYME ACTIVITY __________ & ______________ Conditions that are TOO ACIDIC or TOO HOT cause proteins to ________ or _________ pH temperature UNWIND DENATURE See a movie Choose narrated http://www.desktopfotos.de/Downloads/melt_cd.jpg http://www.nealbrownstudio.com/adm/photo/163_nb_fried_egg.jpg

changes shape ACTIVE SITE CAN’T BIND Denaturing _______ the _______ of the ______________ so enzyme ______________ to ____________ changes shape ACTIVE SITE CAN’T BIND SUBSTRATE _______________ (keeping pH and temperature constant) is ______________ for maintaining ____________________ HOMEOSTASIS IMPORTANT ENZYME FUNCTION Image modified from: http://www.lewport.wnyric.org/jwanamaker/animations/Enzyme%20activity.html

-ASE Many enzyme NAMES end in _____ and the beginning of the name tells what it does DNA Polymerase= “polymerizes” joins monomers to make DNA Protease= breaks down proteins ATP synthase= synthesizes ATP