Enzyme Catalysis | Biochemistry for MCAT PDF Download

 Page 1


General Properties of Enzymes
•Increased reaction rates sometimes 10
6
to 10
12
increase
Enzymes do not change ?G just the reaction rates.
•Milder reaction conditions
•Great reaction specificity
•Can be regulated
Page 2


General Properties of Enzymes
•Increased reaction rates sometimes 10
6
to 10
12
increase
Enzymes do not change ?G just the reaction rates.
•Milder reaction conditions
•Great reaction specificity
•Can be regulated
Substrate specificity
The non-covalent bonds and forces are maximized to 
bind substrates with considerable specificity
•Van der Waals forces
•electrostatic bonds (ionic interactions)
•Hydrogen bonding
•Hydrophobic interaction
A + B          P + Q
Substrates              Products
enz
Page 3


General Properties of Enzymes
•Increased reaction rates sometimes 10
6
to 10
12
increase
Enzymes do not change ?G just the reaction rates.
•Milder reaction conditions
•Great reaction specificity
•Can be regulated
Substrate specificity
The non-covalent bonds and forces are maximized to 
bind substrates with considerable specificity
•Van der Waals forces
•electrostatic bonds (ionic interactions)
•Hydrogen bonding
•Hydrophobic interaction
A + B          P + Q
Substrates              Products
enz
Page 4


General Properties of Enzymes
•Increased reaction rates sometimes 10
6
to 10
12
increase
Enzymes do not change ?G just the reaction rates.
•Milder reaction conditions
•Great reaction specificity
•Can be regulated
Substrate specificity
The non-covalent bonds and forces are maximized to 
bind substrates with considerable specificity
•Van der Waals forces
•electrostatic bonds (ionic interactions)
•Hydrogen bonding
•Hydrophobic interaction
A + B          P + Q
Substrates              Products
enz
+ +
+ + ? + H  NADH  CH CH  NAD  OH CH CH
3 2 3
O
Enzymes are Stereospecific
Yeast 
Alcohol dehydrogenase
Page 5


General Properties of Enzymes
•Increased reaction rates sometimes 10
6
to 10
12
increase
Enzymes do not change ?G just the reaction rates.
•Milder reaction conditions
•Great reaction specificity
•Can be regulated
Substrate specificity
The non-covalent bonds and forces are maximized to 
bind substrates with considerable specificity
•Van der Waals forces
•electrostatic bonds (ionic interactions)
•Hydrogen bonding
•Hydrophobic interaction
A + B          P + Q
Substrates              Products
enz
+ +
+ + ? + H  NADH  CH CH  NAD  OH CH CH
3 2 3
O
Enzymes are Stereospecific
Yeast 
Alcohol dehydrogenase
N
C
H
NH
2
O
+
CH
3
CD
2
OH  +
N
C
H
NH
2
O D
CH
3
C-D
O
+
Pro-R hydrogen gets pulled off
Ox.
Red.
NADD
NAD
+
Y east Alcohol dehydrogenase