Principles of Biochemistry 12 |Glycolysis| Class Notes |HarvardX
Glycolysis
Free Energy of Hydrolysis
Coupling
$PEP + H_ 2O \longrightarrow Pyruvate + P_ i$
$\ \ \ \ \Delta G^ {\circ} = -62 kJ/mol$
$ADP + P_ i \longrightarrow ATP + H_ 2O$
$\ \ \ \ \Delta G^ {\circ} = +30 kJ/mol$
Since they share the common reactacts, this two reaction could be combined together, which was called coupling
$PEP + ADP \overset{Pyruvate Kinase}{\longrightarrow} Pyruvate + ATP$
$\ \ \ \ \Delta G^ {\circ} = -32 kJ/mol$
Coupling:
- Common reactacts
- Catalyzed by one enzyme
Example 1
$PEP + H_ 2O \longrightarrow Pyruvate + P_ i$
$\ \ \ \ \Delta G^ {\circ} = -62 kJ/mol$
$Glucose + P_ i \longrightarrow Glucose^ {_ -} 6 ^{_ -} phosphate + H_ 2O$
$\ \ \ \ \Delta G^ {\circ} = +14 kJ/mol$
The Enzyme were dose not shared by this two reaction
As as result, they can not be coupled
Example 2
$ATP + H_ 2O \longrightarrow ADP + P_ i$
$\ \ \ \ \Delta G^ {\circ} = -30 kJ/mol$
$Glucose + P_ i \longrightarrow Glucose^ {_ -} 6 ^{_ -} phosphate + H_ 2O$
$\ \ \ \ \Delta G^ {\circ} = +14 kJ/mol$
Coupled Reaction:
$Glucose + ATP \overset{hexokinass}{\longrightarrow} Glucose^ {_ -} 6 ^{_ -} phosphate + ADP$
$\ \ \ \ \Delta G^ {\circ} = -16 kJ/mol$
Pyruvate and NADH
.
Principles of Biochemistry 12 |Glycolysis| Class Notes |HarvardX
https://karobben.github.io/2021/04/16/LearnNotes/edx-biochm-12/
