The Tricarboxylic Acid Cycle
Prof. Sylvester L.B. Kajuna
Hubert Kairuki Memorial University
, The Citric Acid Cycle
Key points:
– Also called Tricarboxylic Acid Cycle (TCA) or
Krebs Cycle. Three names mean the same thing.
– Cellular respiration and intermediates for
biosynthesis.
– Conversion of pyruvate to activated acetate
– Reactions of the citric acid cycle
– Anaplerotic reactions to regenerate intermediates
– Regulation of the citric acid cycle
– Conversion of acetate to carbohydrate precursors
in the glyoxylate cycle
, Cellular Respiration
• Process in which cells consume O2 and produce CO2
• Provides more energy (ATP) from glucose than Glycolysis
• Also captures energy stored in lipids and amino acids
• Evolutionary origin: developed about 2.5 billion years ago
• Used by animals, plants, and many microorganisms
• Occurs in three major stages:
- acetyl CoA production
- acetyl CoA oxidation
- electron transfer and oxidative phosphorylation
, Overall Picture
Prof. Sylvester L.B. Kajuna
Hubert Kairuki Memorial University
, The Citric Acid Cycle
Key points:
– Also called Tricarboxylic Acid Cycle (TCA) or
Krebs Cycle. Three names mean the same thing.
– Cellular respiration and intermediates for
biosynthesis.
– Conversion of pyruvate to activated acetate
– Reactions of the citric acid cycle
– Anaplerotic reactions to regenerate intermediates
– Regulation of the citric acid cycle
– Conversion of acetate to carbohydrate precursors
in the glyoxylate cycle
, Cellular Respiration
• Process in which cells consume O2 and produce CO2
• Provides more energy (ATP) from glucose than Glycolysis
• Also captures energy stored in lipids and amino acids
• Evolutionary origin: developed about 2.5 billion years ago
• Used by animals, plants, and many microorganisms
• Occurs in three major stages:
- acetyl CoA production
- acetyl CoA oxidation
- electron transfer and oxidative phosphorylation
, Overall Picture
