1 / 17

Fate of Pyruvate & Citric Acid Cycle

Fate of Pyruvate & Citric Acid Cycle. Introduction of Glucose Metabolism Lecture-3. Fate of pyruvate. 1- Lactate (in cytosol ) Enzyme: lactate dehyrogenase (LDH) in anaerobic glycolysis 2- Acetyl CoA in mitochondria Enzyme: pyruvate dehydrogenase

joella
Download Presentation

Fate of Pyruvate & Citric Acid Cycle

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript


  1. Fate of Pyruvate& Citric Acid Cycle Introduction of Glucose Metabolism Lecture-3

  2. Fate of pyruvate 1- Lactate(in cytosol) Enzyme: lactate dehyrogenase (LDH) in anaerobic glycolysis 2- Acetyl CoA in mitochondria Enzyme: pyruvatedehydrogenase occurs in aerobic glycolysis Acetyl CoA is required for citric acid cycle (CAC) 3- Oxalacetate in mitochondria Enzyme: pyruvatecarboxylase Oxalacetate is required for: 1- Citric acid cycle (condenses with acetyl CoA): to yield energy ATP OR2-Gluconeogenesis (to synthesize glucose)

  3. Fate of Pyruvate Glucose glycolysis Gluconeogenesis No Oxygen No Mitochondria OR BOTH mitochondria PYRUVATE LACTATE OXALACETATE Oxygen & Mitochondria ACETYL CoA CITRIC ACID CYCLE

  4. LACTATE DEHYDROGENASE

  5. FATES OF PYRUVATE

  6. OXIDATIVE DECARBOXYLATION OF PYRUVATE Allosteric Regulation

  7. Formation of acetyl CoA from pyruvate • Pyruvate (end product of aerobic glycolysis) is transported into the mitochondria. • In the mitochondrial matrix, pyruvate is converted to acetyl CoAby pyruvatedehydrogenase complex (multienzyme complex) This reaction is irreversible • Pyruvatedehydrogenase complex is composed of three enzymes & five coenzymes • Coenzymes of the complex are derived from water soluble vitamins: 1- Thiamine pyruphosphate, TPP (derived from thiamine, vitamin B1) 2- NAD+ (derived from niacin) 3- FAD (derived from riboflavin) 4- Lipoic acid 5- Coenzyme A (derived from pantothenic acid)

  8. Pyruvate dehydrogenase complex PYRUVATE ACETYL CoA

  9. Citric acid cycle or,(Krebs cycle)

  10. Citric Acid Cycle Citric acid cycle is the final pathway where the oxidative metabolism of Carbohydrates (as glucose), proteins (amino acids) & lipids (fatty acids) to yield energy (ATP) Acetyl CoAis the end product for oxidation of carbohydrates, lipids & proteins Acetyl CoAcondenses with oxalacetateto form citrate (first reaction of the cycle) 3 NADH are produced = 3 X 3 = 9 ATP (by oxidative phosphorylation) One FADH2 is produced = 1 X 2 = 2 ATP (by oxidative phosphorylation) One ATP is produced (by substrate level phosphorylation) Net = 12 ATP / one acetyl CoA

  11. Citric Acid Cycle CYCLE - SUMMARY Acetyl CoA 3 NAD 3 NADH + H 2 CO2 1 FAD 1 FADH2 1 ADP 1 ATP

  12. KREBS CYCLE REACTIONS (1)

  13. KREBS CYCLE REACTIONS (2) Succinate Thiokinase Substrate-Level Phosphorylation

  14. KREBS CYCLE REACTIONS (3)

  15. KREBS CYCLE: ENERGY YIELD

  16. Citric acid cycle or,(Krebs cycle)

More Related