- |
Transferase Reactions
|
Standard free
energy change
|
Description
|
| Principle 1
|
Energy rich <==> energy rich
Reaction can proceed in either direction
|
Variable
|
Functionally
isoergonic
|
| Principle 2
|
Energy rich ==> energy poor
Reaction from reactants to products is favored
|
Negative
|
Exergonic
|
| Principle 3
|
Energy poor <== energy rich
|
Positive
|
Endergonic
|
| Principle 4
|
Energy poor <==> energy poor
|
Variable
|
Functionally
isoergonic
|
| -
|
Hydrolase Reactions
|
-
|
-
|
| Principle 5
|
Hydrolysis of energy-rich or energy-poor compounds ==> products
Reaction from reactants to products is favored
|
Negative
|
Exergonic
|
| -
|
Decarboxylation Reactions
|
-
|
-
|
| Principle 6
|
RCOO- + H+ ==> RH + CO2
|
Negative
|
Exergonic
|
| -
|
Oxidation-Reduction Reactions
|
-
|
-
|
| Principle 7
|
In simple oxidation-reduction reactions,
the reaction can proceed in either direction
|
Variable
|
Functionally
isoergonic
|
| Principle 8
|
AH + 1/2 O2 ==> AOH
Reaction of oxygen with reductants is favored
|
Negative
|
Exergonic
|
| Principle 9
|
RCHO + H2O + A ==> RCOO- + H+ + AH2
Oxidation of an aldehyde to a carboxylate is favored
|
Negative
|
Exergonic
|
| -
|
Isomerization reactions are bidirectional
Lyase reactions (except decarboxylation reactions) are bidirectional
|
-
|
-
|
| -
|
Ligase reactions can be uni- or bidirectional; count the number
of high energy bonds to determine whether the reaction is uni-
or bidirectional
|
-
|
-
|
- |
Thiolysis reactions are bi-directional: RCH2C(=O)CH2C(=O)~SCoA + CoASH <=> RCH2C(=O)~SCoA + CH3C(=O)~SCoA |
Variable
|
Functionally
isoergonic
|
- |
Phosphorolysis reactions are bi-directional: R-O-R' + H2PO4- <=> R-OPO32- + HOR' + H+ |
Variable
|
Functionally
isoergonic
|
