ENZYMES

Enzymes are proteins Chemical reactions need help to get started. Ex: A fire needs a match to get it started. The reactants (what you start with) need help to carry out the chemical reaction to develop the products

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

Exergonic Reactions Free energy Progress of the reaction ∆G < O EAEA Figure 8.14 A B C D Reactants A C D B Transition state A B CD Products

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

Progress of the reaction Products Course of reaction without enzyme Reactants Course of reaction with enzyme EAEA without enzyme E A with enzyme is lower ∆G is unaffected by enzyme Free energy Figure 8.15

PROTEINS CAN BE ENZYMES SUBSTRATE ENZYME-SUBSTRATE COMPLEX PRODUCTS ENZYME Unchanged & Reusable ENZYME Image modified from: Arrow: ACTIVE SITE

ENZYMES _____ like a _______________ to only _________of _________. Enzymes are ___________ by the reaction and ___________ LOCK AND KEY REUSABLE UNCHANGED FIT ONE KINDSUBSTRATE

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

Progress of the reaction Products Course of reaction without enzyme Reactants Course of reaction with enzyme EAEA without enzyme E A with enzyme is lower ∆G is unaffected by enzyme Free energy Figure 8.15