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Glyconeogenesis. Origin of blood glucose FoodGlycogen (liver) Gluconeogenesis (liver) Blood sugar.

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Presentation on theme: "Glyconeogenesis. Origin of blood glucose FoodGlycogen (liver) Gluconeogenesis (liver) Blood sugar."— Presentation transcript:

1 Glyconeogenesis

2 Origin of blood glucose FoodGlycogen (liver) Gluconeogenesis (liver) Blood sugar

3 Decrease of blood sugar 1.Disfunction of brain Confusion  coma In the absence of alternative substrate - serious consequences (ketonbodies).  diabetes, overdose of insulin Cramps 2.Sympathetic exitement hyperventillation, cold sweat

4 Gluconeogenesis Synthesis of glucose – non carbohydrate precursors –Daily utilisation of glucose: 160 g/day –Glucose - Brain : 120 g/day In humours 20 g In glycogen 190 g Reserves for 24 hours in fasting

5 Gluconeogenesis > fasting for 24 hours Intensive excercise Source: –Lactic acid –aminoacids –Glycerol Organ: –Liver –Kidney (1/10) –Some in brain, in heartmuscle in striated muscleGluconeogenesis

6 Glyconeogenesis  G of glycolysis (glucose  pyruvate) – 20 kcal/mole Decrease in free energy in three stagesDecrease in free energy in three stages 3 different „ways”3 different „ways”

7 Irreversible steps In glycolysis In glyconeogenesis

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9 Irreversible steps of glycolysis 1. Glucose + ATP  glucose-6-P + ADP hexokinase 2. Fruktose-6-P + ATP  fructose-1,6-diP + ADP phosphofructokinase 3. PEP + ADP  pyruvate + ATP Piruvate kinase

10 Pyruvate  oxalacetate  phosphoenolpyruvate Pyruvate + CO 2 + ATP + H 2 O  oxaloacetate + ADP + P i + 2H + oxaloacetate oxaloacetate + GTP  PEP + GDP + CO 2 Pyruvate-carboxylase Phosphoenolpyruvate carboxykinase

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13 Pyruvate carboxylase Intramitochondrial Prosthetic group: biotin

14 Allosteric activator: Acethyl~CoA Anaplerotic reaction Signal – for more oxaloacetate

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16 Oxalacetate Gluconeogenesis Citric acid cycle High amount of ATP Low amount of ATP

17 Irreversible steps of glyconeogenesis 2. fructose-1,6-diP + H 2 O  fructose-6-P +P i 3. glucose-6-P + H 2 O  glucose +P i Fructose-1,6-diP Glucose-6-phosphatase Absence in brain and muscle

18 Bloodplasma Plasmamembrane of hepatocytes GluT2 Cytosol ER-lumen Glucose-6-P Glucse-6-phosphatase Glucose PiPi GluT7

19 The gluconeogenesis is „expensive” 2 pyruvate + 4 ATP + 2 GTP + 2 NADH + 4 H 2 O    Glucose + 4 ADP + 2 GDP + 2 NAD H + Glycolysis Glucose + 2 ADP + 2 P i + 2 NAD +   2 pyruvate+ 2 ATP + 2 NADH + 2H H 2 O Irreversible

20 Laktát Piruvát Oxálacetát PEP Mitokondrium Citoszól NAD + NADH + H + CO 2 Piruvát karboxiláz Mitokonriális PEP karboxikináz Piruvát Oxálacetát Malát Oxálacetát NADH + H + NAD + NADH + H + CO 2 Citoplazmatikus PEP karboxikináz CO 2

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23 Glucoplastic aminoacids Pyruvate –Alanine –Cystein –Glycine –Serine –Triptophane.  -ketoglutarate –Arginine –Glutamate –Glutamine –Hisztidine –Proline Succinyl-CoA –Isoleucine –Metionine –Treonine –Valine Fumarate –Fenilalanin –Tirozin Oxalacetate –Aspartate –Asparagine

24 Blood Glycolysis Lactate(2) H + (2) ADP + (2) Pi (2) ATP Blood Glucose Work

25 Cori cycle Glucose Lactic acid pyruvate LiverMusle, red blood cells Prevents lactic acidosis follow the glycolysis

26 Alanin cyclus Glucose Piruvate Alanin Piruvate LiverMuscle Transport of aminoacids in nontoxic form Alanin  -ketoglutarate glutamate NH 3 urea Amino acid NH 2 Glutamate  -ketoglutarate

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28 Glucose tolerance test


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