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Metabolism of saccharides - exercise -

Metabolism of saccharides - exercise -. Vladimíra Kvasnicová. Glucose enter the cells by. free diffusion facilitated diffusion active transport secondary active transport. Glucose enter the cells by. free diffusion facilitated diffusion active transport secondary active transport.

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Metabolism of saccharides - exercise -

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  1. Metabolism of saccharides- exercise - Vladimíra Kvasnicová

  2. Glucose enter the cells by • free diffusion • facilitated diffusion • active transport • secondary active transport

  3. Glucose enter the cells by • free diffusion • facilitated diffusion • active transport • secondary active transport

  4. Insulin-dependent transport of glc into the cell is found in the • liver • erytrocyte • adipose tissue • muscle

  5. Insulin-dependent transport of glc into the cell is found in the • liver • erytrocyte • adipose tissue • muscle

  6. Glucose transport into cells: facilitated diffusion(protein transporter GLUT – various types) ERYTROCYTES NERVOUS TISSUE - insulin-independent transport The figure is found at http://www.kumc.edu/research/medicine/biochemistry/bioc800/car02fra.htm (Jan 2007)

  7. HEPATOCYTES - insulin-independent transport The figure is found athttp://www.kumc.edu/research/medicine/biochemistry/bioc800/car02fra.htm (Jan 2007)

  8. FATTY TISSUE MUSCLES - insulin-DEPENDENT transport insulin increases number of glc transporters The figure is found athttp://www.kumc.edu/research/medicine/biochemistry/bioc800/car02fra.htm (Jan 2007)

  9. Secondary-active transport of GLC: symport with Na+ - small intestine, kidneys The figure was adopted fromDevlin, T. M. (editor): Textbook of Biochemistry with Clinical Correlations, 4th ed. Wiley‑Liss, Inc., New York, 1997. ISBN 0‑471‑15451‑2

  10. Glucose from a diet can be used • as an energy source for cells • for glycogen synthesis • for formation of fat (= energy store) • as a main substrate for production of NADPH

  11. Glucose from a diet can be used • as an energy source for cells • for glycogen synthesis • for formation of fat (= energy store) • as a main substrate for production of NADPH

  12. Glc-6-P !!! + NADPH = hepatocyte The figure is found athttp://www.kumc.edu/research/medicine/biochemistry/bioc800/car02fra.htm (Jan 2007)

  13. Glycolysis(= oxidative cleavage of glucose) • is located in a mitochondrion • can proceed under anaerobic conditions as well • produces 2 moles of pyruvate / 1 mole of Glc • generates 2 moles of ATP as a net energy acquisition

  14. Glycolysis(= oxidative cleavage of glucose) • is located in a mitochondrion • can proceed under anaerobic conditions as well • produces 2 moles of pyruvate / 1 mole of Glc • generates 2 moles of ATP as a net energy acquisition

  15. Products of aerobic glycolysis 2 Products of anaerobic glycolysis NADHwas consumed in conversion of pyruvate to lactate 2 The figure is found athttp://www.kumc.edu/research/medicine/biochemistry/bioc800/car02fra.htm (Jan 2007)

  16. Enzyme hexokinase • catalyzes esterification of glucose • has higher affinity to glucose than glucokinase • phosphorylates fructose as well • is found in a cytoplasm of many cells

  17. Enzyme hexokinase • catalyzes esterification of glucose • has higher affinity to glucose than glucokinase • phosphorylates fructose as well • is found in a cytoplasm of many cells

  18. IRREVERSIBLE REACTION The figure is found athttp://www.kumc.edu/research/medicine/biochemistry/bioc800/car02fra.htm (Jan 2007)

  19. KmKm The glucokinase has higher value of Kmthan hexokinase glucokinase has lower affinity to glucose (it needs more glucose to reach the reaction velocity of Vmax/2) The figure is found at http://www.kumc.edu/research/medicine/biochemistry/bioc800/car02fra.htm (Jan 2007)

  20. Enzyme 6-phosphofructokinase-1 (PFK-1) • is a main regulatory enzyme of glycolysis • converts fructose-1,6-bisphosphate to fructose-6-phosphate • is activated by citrate and  ATP/ADP • is regulated by insulin

  21. Enzyme 6-phosphofructokinase-1 (PFK-1) • is a main regulatory enzyme of glycolysis • converts fructose-1,6-bisphosphate to fructose-6-phosphate • is activated by citrate and  ATP/ADP • is regulated by insulin

  22. IRREVERSIBLE REACTION The figure is found athttp://www.kumc.edu/research/medicine/biochemistry/bioc800/car02fra.htm (Jan 2007)

  23. NADH+H+ forming in glycolysis • is a coenzyme of oxidoreductases • can be reoxidized back to NAD+ in a conversion of pyruvate to lactate • can be used in a reduction of malate to oxaloacetate • is a source of reducing equivalents enteringa respiratory chain, but only under aerobic conditions

  24. NADH+H+ forming in glycolysis • is a coenzyme of oxidoreductases • can be reoxidized back to NAD+ in a conversion of pyruvate to lactate • can be used in a reduction of malate to oxaloacetate • is a source of reducing equivalents enteringa respiratory chain, but only under aerobic conditions

  25. The figure is found athttp://www.kumc.edu/research/medicine/biochemistry/bioc800/car02fra.htm (Jan 2007)

  26. The figure is found athttp://www.kumc.edu/research/medicine/biochemistry/bioc800/car02fra.htm (Jan 2007)

  27. Transport of reducing equivalents to mitochondria The figure was adopted fromDevlin, T. M. (editor): Textbook of Biochemistry with Clinical Correlations, 4th ed. Wiley‑Liss, Inc., New York, 1997. ISBN 0‑471‑15451‑2 MALATE-ASPARTATE SHUTTLE

  28. GLYCEROL PHOSPHATE SHUTTLE The figure was adopted fromDevlin, T. M. (editor): Textbook of Biochemistry with Clinical Correlations, 4th ed. Wiley‑Liss, Inc., New York, 1997. ISBN 0‑471‑15451‑2

  29. 2,3-bisphosphoglycerate (2,3-BPG) • belongs among energy rich compounds • is formed from glyceraldehyde-3-phosphate by phosphorylation using inorganic phosphate • can be transformed to 3-phosphoglycerate, ATP is simultaneously formed from ADP • is formed only in the liver as a shunt of glycolysis

  30. 2,3-bisphosphoglycerate (2,3-BPG) • belongs among energy rich compounds • is formed from glyceraldehyde-3-phosphate by phosphorylation using inorganic phosphate • can be transformed to 3-phosphoglycerate, ATP is simultaneously formed from ADP • is formed only in the liver as a shunt of glycolysis

  31. 2,3-BPG shunt IN ERYTROCYTES: 2,3-BPG  affinity of Hb to O2 The figure was adopted fromDevlin, T. M. (editor): Textbook of Biochemistry with Clinical Correlations, 4th ed. Wiley‑Liss, Inc., New York, 1997. ISBN 0‑471‑15451‑2

  32. ATP is formed in the reactions of glycolysis • phosphoenolpyruvate (PEPA) → pyruvate • glucose → glucose-6-phosphate • fructose-1,6-bisphosphate→ fructose-6-phosphate • glyceraldehyde-3-phosphate→ 1,3-bisphosphoglycerate

  33. ATP is formed in the reactions of glycolysis • phosphoenolpyruvate (PEPA) → pyruvate • glucose → glucose-6-phosphate ATP is consumed • fructose-1,6-bisphosphate = not energy-rich comp.→ fructose-6-phosphate • glyceraldehyde-3-phosphate→ 1,3-bisphosphoglycerate

  34. IRREVERSIBLE REACTION = substrate level phosphorylation (ATP formation using energy released from cleavage of an energy rich compound = macroergic compound) The figure is found athttp://www.kumc.edu/research/medicine/biochemistry/bioc800/car02fra.htm (Jan 2007)

  35. Pi + = substrate level phosphorylation The figure is found athttp://www.kumc.edu/research/medicine/biochemistry/bioc800/car02fra.htm (Jan 2007)

  36. Pyruvate can be transformed by • carboxylation to acetyl-CoA • reduction to lactate • oxidative decarboxylation to oxaloacetate • transamination to aspatate

  37. Pyruvate can be transformed by • carboxylation to acetyl-CoA • reduction to lactate • oxidative decarboxylation to oxaloacetate • transamination to aspatate

  38. = transamination = reduction = carboxylation = oxidative decarboxylation The figure is found athttp://www.kumc.edu/research/medicine/biochemistry/bioc800/car02fra.htm (Jan 2007)

  39. Choose correct statements about regulation of glycolysis • it is activated by insulin • it is activated by glucagon • regulatory enzymes of glycolysis are kinases •  pH inhibits glycolysis

  40. Choose correct statements about regulation of glycolysis • it is activated by insulin • it is activated by glucagon • regulatory enzymes of glycolysis are kinases •  pH inhibits glycolysis

  41. Regulation of glycolysis

  42. Enzymes of gluconeogenesis(= synthesis of glucose „de novo“) • are found in a cytoplasm only • are active mainly in a brain and erytrocytes • are completely the same as enzymes of glycolysis (catalyze oposite reactions of glycolysis) • are not found in the liver

  43. Enzymes of gluconeogenesis(= synthesis of glucose„de novo“) • are found in a cytoplasm only • are active mainly in a brain and erytrocytes • are completely the same as enzymes of glycolysis (they catalyze oposite reactions of glycolysis) • are not found in the liver gluconeogenesis proceeds only in the liver and the kidneys

  44. in mitochondria only The figure is found at http://www.kumc.edu/research/medicine/biochemistry/bioc800/car02fra.htm (lJan 2007)

  45. Gluconeogenesis The figure is found athttp://www.kumc.edu/research/medicine/biochemistry/bioc800/car02fra.htm (Jan 2007)

  46. Choose substrates of gluconeogenesis • acetyl-CoA • pyruvate • glycerol • lactate

  47. Choose substrates of gluconeogenesis • acetyl-CoA it can not be converted to pyruvate • pyruvate • glycerol • lactate

  48. Cori cycle and muscle The figure was adopted fromDevlin, T. M. (editor): Textbook of Biochemistry with Clinical Correlations, 4th ed. Wiley‑Liss, Inc., New York, 1997. ISBN 0‑471‑15451‑2

  49. Glucose-alanine cycle The figure was adopted fromDevlin, T. M. (editor): Textbook of Biochemistry with Clinical Correlations, 4th ed. Wiley‑Liss, Inc., New York, 1997. ISBN 0‑471‑15451‑2

  50. = tuk The figure was adopted fromDevlin, T. M. (editor): Textbook of Biochemistry with Clinical Correlations, 4th ed. Wiley‑Liss, Inc., New York, 1997. ISBN 0‑471‑15451‑2

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