ENZYMES ACTIVATION ENERGY & REACTION GRAPHS ADDITIONAL GRAPHS & PRACTICE PROBLEMS
An enzyme: • • • is a protein is a biologic catalyst is very specific is not used up in a chemical reaction has an active site that its substrate binds to lowers the activation energy of a reaction
Enzymes
Enzymes
Types of Chemical Reactions ENDERGONIC EXERGONIC • REACTIONS IN WHICH THE ENERGY OF THE PRODUCT(S) IS GREATER THAN THE ENERGY OF THE REACTANTS • REACTIONS IN WHICH THE ENERGY OF THE REACTANTSIS GREATER THAN ENERGY OF THE PRODUCTS • THAT IS: ENERGY HAS BEEN ABSORBED IN THE REACTION • THAT IS: ENERGY HAS BEEN RELEASED IN THE REACTION
(don’t worry about ∆G in diagram below)
Endergonic & Exergonic Energy Graphs
What is activation energy? • It is the nrg necessary to get the reaction to go forward (even if it is an exergonic reaction).
What is activation energy?
Enzymes Lower the Activation Energy so the Reaction occurs faster & requires less energy • Red line in graph represents how much energy needed to get from reactants products • Blue line represents how much energy needed when an enzyme is present
Enzymes Lower the Activation Energy so the Reaction occurs faster & requires less energy • The peak of the red line (or blue line) coincides with the point where the bonds in the reactants of the reaction are weakest. It is also called a transition state