Download Chapter 12 (part 1) - University of Nevada, Reno

Chapter 12 (part 1)
Citric Acid Cycle
Gylcolysis
Electron Transport and
Oxidative phosphorylation
TCA Cycle
Entry into the TCA Cycle
Pyruvate Dehydrogenase
Citrate Synthase
• Only step in TCA cycle that involves the
formation of a C-C bond
Aconitase
Isocitrate Dehydrogenase
 -Ketoglutarate Dehydrogenase
Succinyl-CoA Synthetase
Fumarase
Malate Dehydrogenase
Reduced Coenzymes Fuel ATP
Production
• Acetyl-CoA + 3 NAD+ + Q + GDP + Pi +2 H20 
HS-CoA + 3NADH + QH2 + GTP + 2 CO2 + 2 H+
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Isocitrate Dehydrogenase
-ketoglutarate dehydrogenase
Succinyl-CoA synthetase
Sunccinate dehydrogenase
Malate Dehydrogenase
1 NADH=2.5 ATP
1 NADH=2.5 ATP
1 GTP=1 ATP
1 QH2=1.5 ATP
1 NADH=2.5 ATP
• Total of 10 ATPs gained from oxidation of 1 AcetylCoA
Regulation
of TCA
Cycle
Protein/amino acid
Catabolites feed
Into the TCA Cycle
Fats breakdown
and feed
into the TCA Cycle
TCA Cycle provides
intermediates for
many biosynthetic
processes
The Anaplerotic Reactions
The "filling up" reactions
• PEP carboxylase - converts PEP to oxaloacetate
• Pyruvate carboxylase - converts pyruvate to
oxaloacetate
• Malic enzyme converts pyruvate into malate
Following the carbons
through the TCA cycle