Major pathways of glucose utilization

Nội dung text: Major pathways of glucose utilization

1. CELLULAR RESPIRATION STAGES OF CELLULAR RESPIRATION • Glycolysis • The Krebs Cycle • The Electron Transport Chain (ETC)
2. WHERE DOES CELLULAR RESPIRATION TAKE PLACE? It takes place in two parts of the cell Glycolysis occurs in the Cytoplasm Krebs Cycle & ETC takeplace in the Mitochondrion Mitochondrion
3. Aerobic Cellular Respiration
4. Glycolysis
5. Overall equation for glycolysis
6. 1. Phosphorylation of Glucose
7. The phosphohexose isomerase reaction
8. 4. Cleavage of Fructose 1,6-Bisphosphate
9. 6. Oxidation of Glyceraldehyde 3-Phosphate to 1,3-Bisphosphoglycerate
10. 7. Phosphoryl Transfer from 1,3-Bisphosphoglycerate to ADP
11. Phosphoglycerate mutase reaction
12. 10. Transfer of the Phosphoryl Group from Phosphoenolpyruvate to ADP
13. The Entry of Fructose into Glycolysis Much of the ingested fructose is metabolized by the liver, using the fructose 1-phosphate pathway. The first step is the phosphorylation of fructose to fructose 1- phosphate by fructokinase. Fructose 1-phosphate is then split into glyceraldehyde and dihydroxyacetone phosphate, an intermediate in glycolysis, by a specific fructose 1 -phosphate aldolase. Glyceraldehyde is then phosphorylated to glyceraldehyde 3-phosphate, a glycolytic intermediate, by triose kinase.
14. The Entry of Galactose into Glycolysis Galactose is converted into glucose 6-phosphate in four steps. The first reaction is the phosphorylation of galactose to galactose 1- phosphate by galactokinase.
15. Entry of glycogen, starch, disaccharide, hexoses into preparatory stage of glycolysis
16. FERMENTATION ❖ Occurs when O2 NOT present (anaerobic) ❖Lactic Acid fermentation ❖Alcoholic fermentation ❖Nets only 2 ATP
17. Opposing pathways of glycolysis and gluconeogenesis
18. Opposing pathways of glycolysis and gluconeogenesis
19. Alternative paths from pyruvate to PEP
20. Pentose Phosphate Pathway of Glucose Oxidation • Also called the phosphogluconate pathway or the hexose monophosphate pathway • In most animal tissues, the major catabolic fate of glucose 6-phosphate is glycolytic breakdown to pyruvate • Glucose 6-phosphate has other catabolic fates: oxidation of glucose 6-phosphate to pentose phosphates (ribose phosphate) → pentose phosphate pathway
21. Oxidative rxns of pentose phosphate path
22. Nonoxidative rxns of pentose phosphate path
23. Nonoxidative rxns of pentose phosphate path
24. Summary of pentose phosphate path • In term of energy: - Not directly generate ATP - From 12 (NADPH+H+) via ETC generating 12x3=36 ATP • In term of metabolism: - Providing pentose (for biosynthesis of nucleotide, CoA, DNA, RNA)
25. Metabolic regulation
26. The Citric Acid Cycle (KREBS) • Production of Acetyl-CoA (Activated Acetate) • Reactions of the Citric Acid Cycle • Regulation of the Citric Acid Cycle • The Glyoxylate Cycle
27. Catabolism of proteins, fats, and carbohydrates in the three stages of cellular respiration
28. KREBS CYCLE Reactions of the citric acid cycle: 8 steps
29. Coenzyme A (CoA)
30. Reactions of the citric acid cycle: 8 steps
31. 1. Formation of Citrate
32. Structure of citrate synthase
33. 3. Oxidation of Isocitrate to α-Ketoglutarate and CO2
34. 5. Conversion of Succinyl-CoA to Succinate
35. Synthases and Synthetases; Ligases and Lyases; Kinases, Phosphatases, and Phosphorylases • Ligases: catalyze condensation reactions in which two atoms are joined, using ATP or another energy source • Lyases: catalyze cleavages (or, in the reverse direction, additions) in which electronic rearrangements occur
36. Synthases and Synthetases; Ligases and Lyases; Kinases, Phosphatases, and Phosphorylases • Phosphorylases: catalyse phosphorolysisis: a displacement reaction in which phosphate is the attacking species and becomes covalently attached at the point of bond breakage • Phosphatases: catalyse dephosphorylation,the removal of a phosphoryl group from a phosphate ester with water as the attacking species
37. 7. Hydration of Fumarate to Malate
38. Role of the citric acid cycle in anabolism
39. Glyoxylate (2C) cycle produces Four-Carbon Compounds (oxaloacetate) from Acetate
40. Relationship between glyoxylate & citric acid cycles
41. NADH & FADH2 are coenzymes for tranferring H2 & for synthesis of ATP of ETC 1 NADH generates 3 ATP 1 FADH2 generates 2 ATP 1 GTP equals 1 ATP
42. WHAT CARRIES THE ELECTRONS IN CELLULAR RESPIRATION ? • FAD+ (Flavin- Adenine Dinucleotide) • FAD+: Coenzyme • Reduced to FADH2
43. ELECTRON TRANSPORT CHAIN (ETC): RESPIRATION CHAIN • Occurs Across Inner Mitochondrial membrane • High-energy electrons enter ETC • Uses NADH and FADH2 produced from Krebs cycle to make ATP – NADH = 3 ATP’s – FADH2 = 2 ATP’s – Produce 34 ATP, H2O – energy is used to transport hydrogen ions across the inner membrane
44. ATP produced from Cellular respiration (from 1 Glucose) • Glycolysis: produce 2ATP • The Krebs Cycle: produce 2ATP • The Electron Transport Chain (ETC): produce 34ATP • Total: 1Glucose → 38ATP 102
45. • Chu trình Krebs là giai đoạn cuối của quá trình oxy hóa khử sinh học chung cho các quá trình TĐC • Là nguồn cung cấp hàng loạt khung carbon làm nguyên liệu tổng hợp các hợp chất sinh học khác
46. Chu trình Krebs có sự tham gia xúc tác của hàng loạt vitamin nhóm B • Vitamin B3 (PP) NADH • Vitamin B2 FAD • Vitamin B5 CoA • Vitamin B1 Thiamin (Pyruvatedecarboxylase) • Vitamin B9 Lipoic acid
47. Vitamin B3
48. Vitamin B1 (TTP)