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Specialty Chemistry Forums => Biochemistry and Chemical Biology Forum => Topic started by: domique on March 23, 2017, 11:14:59 AM

Title: ATPs produced from the complete oxidation of fumarate
Post by: domique on March 23, 2017, 11:14:59 AM


Hello,
I've got some doubts about the number of ATPs produced from the complete oxidation of fumarate...is it 15 or 12,5?Do I have to count NADPH?
 
Fumarate -> Malate
Malate -> Piruvate ( 1 NADPH=2,5 ATP)
Piruvate-> Acetyl CoA (1 NADH=2,5 ATP)
Acetyl CoA ->Krebs Cycle ( 10 ATP)
 
1 FADH2=1,5 ATP
1 NADH  =2,5 ATP
 

Title: Re: ATPs produced from the complete oxidation of fumarate
Post by: Babcock_Hall on March 23, 2017, 08:57:17 PM
Which sub-cellular compartment are we discussing?  What do you propose as a mechanism for donation of electrons from NADPH into the electron-transport chain?
Title: Re: ATPs produced from the complete oxidation of fumarate
Post by: domique on March 24, 2017, 03:53:43 PM
Which sub-cellular compartment are we discussing?  What do you propose as a mechanism for donation of electrons from NADPH into the electron-transport chain?

So, malate to pyruvate reaction is catalysed by cytosolic malate dehydrogenase (malic enzyme),which is found in the mitochondrial matrix and is a source for synthesis of NADPH that can be used for the reductive biosynthesis....now what I want to know is if at the end of the oxidation of fumarate I have to consider the equivalents of ATPs from NADPH (2,5 ATPs) or not...
Title: Re: ATPs produced from the complete oxidation of fumarate
Post by: Babcock_Hall on March 27, 2017, 04:34:57 PM
Which sub-cellular compartment are we discussing?  What do you propose as a mechanism for donation of electrons from NADPH into the electron-transport chain?

So, malate to pyruvate reaction is catalysed by cytosolic malate dehydrogenase (malic enzyme),which is found in the mitochondrial matrix and is a source for synthesis of NADPH that can be used for the reductive biosynthesis....now what I want to know is if at the end of the oxidation of fumarate I have to consider the equivalents of ATPs from NADPH (2,5 ATPs) or not...
I am confused by what you wrote.  Malate dehydrogenase converts malate to oxaloacetate.  Malic enzyme (which produces pyruvate) is indeed cytoplasmic, but it is not found in the mitochondrial matrix, to the best of my knowledge.

I would assume that NADPH is being used biosynthetically; therefore, I would not assume that it is used to make ATP.