enzymes activation energy & reaction...
TRANSCRIPT
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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
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Enzymes
-
Enzymes
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Types of Chemical Reactions
ENDERGONIC
• REACTIONS IN WHICH
THE ENERGY OF THE
PRODUCT(S) IS
GREATER THAN THE
ENERGY OF THE
REACTANTS
• THAT IS: ENERGY HAS
BEEN ABSORBED IN
THE REACTION
EXERGONIC
• REACTIONS IN WHICH
THE ENERGY OF THE
REACTANTSIS
GREATER THAN
ENERGY OF THE
PRODUCTS
• THAT IS: ENERGY HAS
BEEN RELEASED IN
THE REACTION
-
(don’t worry about ∆G in diagram below)
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Endergonic & Exergonic Energy
Graphs
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What is activation energy?
• It is the nrg necessary to get the reaction to go
forward (even if it is an exergonic reaction).
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What is activation energy?
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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
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• http://www.youtube.com/watch?v=VbIaK6PLrR
M
• http://www.stolaf.edu/people/giannini/flashani
mat/enzymes/transition%20state.swf
http://www.youtube.com/watch?v=VbIaK6PLrRMhttp://www.stolaf.edu/people/giannini/flashanimat/enzymes/transition state.swf