際際滷

際際滷Share a Scribd company logo

Overview about Complete oxidation of glucose.pptx

Download as PPTX, PDF
Abdelrhman Abooda
Abdelrhman Abooda

Overview about Complete oxidation of glucose

1 of 40
Download to read offline
Complete Oxidation of Glucose
Complete Oxidation Complete Oxidation Mechanism. Partial Oxidation Mechanism. Oxidation of Glucose Glycolysis. Glycolysis Pathways Importance of Glycolysis Kreb's cycle Pathway Importance of Kreb's cycle CONTENTS
COMPLETE OXIDATION Complete oxidation occurs when the oxygen-to-carbon ratio is at least stoichiometric to produce carbon dioxide and water. The reactions are spontaneous and generate large amounts of energy.
COMPLETE OXIDATION MECHANISM.
PARTIAL OXIDATION MECHANISM.
COMPLETE OXIDATION Glucose can be used by two pathways i.e. aerobic and anaerobic respiration. Glucose is completely oxidised only in the presence of oxygen and results in the release of energy. It undergoes three steps to finally reach its fate - glycolysis, Kreb's cycle and electron transport chain reaction. In anaerobic respiration, glucose undergoes partial oxidation and results in the release of energy which is comparitvely less to the energy released during aerobic respiration.
WHERE IS GLUCOSE COMPLETELY OXIDIZED? Glycolysis only represents the first pathway involved in glucose oxidation. The remaining pathways involve the Krebs cycle and the electron transport chain, where the oxidation process is completed. Where is glucose completely oxidized? Glycolysis occurs within the cytoplasm of the cell. The products of glycolysis are then transported into the mitochondria, where the Krebs cycle and processing in the mitochondria take place.
OXIDATION OF GLUCOSE There are two pathways for oxidation of Glucose. 1) Major pathways: Glycolysis. Kreb's cycle. 2) Minor pathway: Pentose shunt
GLYCOLYSIS PATHWAY
GLYCOLYSIS: ENERGY INVESTMENT In reactions 1 to 5 of glycolysis, energy is required to add phosphate groups to glucose. glucose is converted to two three-carbon molecules.
GLYCOLYSIS: ENERGY GENERATING In reactions 6 to 10 of glycolysis, energy is obtained from the hydrolysis of the energy-rich phosphate compounds. four ATP are synthesized.
GLYCOLYSIS: REACTION 1 In reaction 1, phosphorylation, a phosphate group is transferred from ATP to glucose. glucose-6-phosphate and ADP are produced. the enzyme hexokinase catalyzes the reaction.
GLYCOLYSIS: REACTION 2 In reaction 2, isomerization, glucose-6-phosphate, the aldose from reaction 1, is converted to fructose-6-phosphate. the isomerization is catalyzed by the enzyme phosphoglucose isomerase.
GLYCOLYSIS: REACTION 3 In reaction 3, phosphorylation, hydrolysis of another ATP provides a second phosphate group. the phosphate group is transferred to fructose-6-phosphate, producing fructose-1,6-bisphosphate. a second kinase enzyme called phosphofructokinase catalyzes the reaction.
GLYCOLYSIS: REACTION 4 In reaction 4, cleavage, fructose-1,6-bisphosphate is split into two three-carbon phosphate isomers. the enzyme aldolase produces dihydroxyacetone phosphate and glyceraldehyde-3-phosphate.
GLYCOLYSIS: REACTION 5 In reaction 5, isomerization, dihydroxyacetone phosphate undergoes isomerization catalyzed by triose phosphate isomerase. a second molecule of glyceraldehyde-3-phosphate is produced, which can be oxidized. all six carbon atoms from glucose are contained in two identical triose phosphates.
GLYCOLYSIS: REACTION 6 In reaction 6, oxidation and phosphorylation, the aldehyde group of each glyceraldehyde-3-phosphate is oxidized to a carboxyl group. NAD+ is reduced to NADH and H+. a phosphate group is transferred to each of the new carboxyl groups, forming two molecules of 1,3-bisphosphoglycerate.
GLYCOLYSIS: REACTION 7 In reaction 7, phosphate transfer, a phosphate group from each 1,3-bisphosphoglycerate is transferred to two ADP molecules by phosphoglycerate kinase. two molecules of the high-energy compound ATP are produced.
GLYCOLYSIS: REACTION 8 In reaction 8, isomerization, two 3-phosphoglycerate molecules undergo isomerization by phosphoglycerate mutase. the phosphate group is moved from carbon 3 to carbon 2, yielding two molecules of 2-phosphoglycerate.
GLYCOLYSIS: REACTION 9 In reaction 9, dehydration, each phosphoglycerate molecule undergoes dehydration by the enzyme enolase. two high-energy phosphoenolpyruvate molecules are produced.
GLYCOLYSIS: REACTION 10 In reaction 10, phosphate transfer, phosphate groups from two phosphoenolpyruvate molecules are transferred by pyruvate kinase to yield two ADP, two pyruvate, and two ATP. a fourth kinase enzyme transfers a phosphate with ATP production.
GLYCOLYSIS: OVERALL REACTION In glycolysis, two ATP add phosphate to glucose and fructose-6-phosphate. four ATP are formed in energy generation by direct transfers of phosphate groups to four ADP. there is a net gain of 2 ATP and 2 NADH.
FRUCTOSE AND GALACTOSE Other monosaccharides, such as fructose and galactose, can enter glycolysis after they are converted to intermediates. In muscles and kidneys, fructose is phosphorylated to fructose-6-phosphate, which enters glycolysis in reaction 3. Galactose reacts with ATP to yield galactose-1-phosphate, which is converted to glucose-6- phosphate, which then enters glycolysis at reaction 2.
FRUCTOSE AND GALACTOSE Galactose and fructose form intermediates that enter the glycolysis pathway to be metabolized.
REGULATION OF GLYCOLYSIS Glycolysis is regulated by three enzymes. In reaction 1, hexokinase is inhibited by high levels of glucose-6-phosphate, which prevents the phosphorylation of glucose. In reaction 3, phosphofructokinase, an allosteric enzyme, is inhibited by high levels of ATP and activated by high levels of ADP and AMP. In reaction 10, pyruvate kinase, another allosteric enzyme, is inhibited by high levels of ATP or acetyl CoA.
IMPORTANCE OF GLYCOLYSIS Nearly all of the energy used by living cells comes from the energy in the bonds of the sugar glucose. Glycolysis is the first pathway used in the breakdown of glucose to extract energy. It takes place in the cytoplasm of both prokaryotic and eukaryotic cells. It was probably one of the earlier metabolic pathways to evolve since it is used by nearly all of the organisms on earth.
IMPORTANCE OF GLYCOLYSIS The process doesnt use oxygen and is, therefore, anaerobic. Glycolysis is the first of the main metabolic pathways of cellular respiration to produce energy in the form of ATP. Overall, the process of glycolysis produces a net gain of two pyruvate molecules, two ATP molecules, and two NADH molecules for the cell to use for energy.
KREB'S CYCLE The Krebs cycle or TCA cycle (tricarboxylic acid cycle) or Citric acid cycle is a series of enzyme catalysed reactions occurring in the mitochondrial matrix, where acetyl-CoA is oxidised to form carbon dioxide and coenzymes are reduced, which generate ATP in the electron transport chain.
KREB'S CYCLE STEPS
KREB'S CYCLE STEPS After glycolysis, in aerobic organisms, the pyruvate molecules are carboxylated to form acetyl CoA and CO2. Oxidative Decarboxylation of pyruvate to Acetyl CoA
STEP 1: CONDENSATION OF ACETYL COA WITH OXALOACETATE The first step of the citric acid cycle is the joining of the four-carbon compound oxaloacetate (OAA) and a two-carbon compound acetyl CoA. The oxaloacetate reacts with the acetyl group of the acetyl CoA and water, resulting in the formation of a six-carbon compound citric acid, CoA.
STEP 2: ISOMERIZATION OF CITRATE INTO ISOCITRATE Now, for further metabolism, citrate is converted into isocitrate through the formation of intermediate cis- aconitase. This reaction is a reversible reaction catalyzed by the enzyme aconitase.
STEP 3: OXIDATIVE DECARBOXYLATIONS OF ISOCITRATE The third step of the citric acid cycle is the first of the four oxidation-reduction reactions in this cycle. Isocitrate is oxidatively decarboxylated to form a five-carbon compound, 留-ketoglutarate catalyzed by the enzyme isocitrate dehydrogenase. This reaction, like the second reaction, is a two-step reaction.
STEP 4: OXIDATIVE DECARBOXYLATION OF - KETOGLUTARATE This step is another one of the oxidation-reduction reactions where 留- ketoglutarate is oxidatively decarboxylated to form a four-carbon compound, succinyl-CoA, and CO2.
STEP 5: CONVERSION OF SUCCINYL-COA INTO SUCCINATE In the next step, succinyl-CoA undergoes an energy-conserving reaction in which succinyl-CoA is cleaved to form succinate. This reaction is accompanied by phosphorylation of guanosine diphosphate (GDP) to guanosine triphosphate (GTP).
STEP 6: DEHYDRATION OF SUCCINATE TO FUMARATE Here, the succinate formed from succinyl-CoA is dehydrogenated to fumarate catalyzed by the enzyme complex succinate dehydrogenase found in the intramitochondrial space.
STEP 7: HYDRATION OF FUMARATE TO MALATE The fumarate is reversibly hydrated to form L-malate in the presence of the enzyme fumarate hydratase.
STEP 8: DEHYDROGENATION OF L-MALATE TO OXALOACETATE The last step of the citric acid cycle is also an oxidation-reduction reaction where L-malate is dehydrogenated to oxaloacetate in the presence of L-malate dehydrogenase, which is present in the mitochondrial matrix.
IMPORTANCE OF KREBS CYCLE The Krebs cycle is the second of three stages of cellular respiration, in which glucose, fatty acids and certain amino acids, the so-called fuel molecules, are oxidized (see Figure). The oxidation of these molecules is primarily used to transform the energy contained in these molecules into ATP. ATP provides for example energy for muscle contractions and can therefore be referred to as "energy currency" of the cells. The Krebs cycle has two important functions. One is production of intermediate compounds important in the synthesis of substances such as amino and fatty acids. The other is formation of large quantities of ATP that provides energy for various synthetic processes.
Thanks Any Questions?

More Related Content

Overview about Complete oxidation of glucose.pptx

  • 2. Complete Oxidation Complete Oxidation Mechanism. Partial Oxidation Mechanism. Oxidation of Glucose Glycolysis. Glycolysis Pathways Importance of Glycolysis Kreb's cycle Pathway Importance of Kreb's cycle CONTENTS
  • 3. COMPLETE OXIDATION Complete oxidation occurs when the oxygen-to-carbon ratio is at least stoichiometric to produce carbon dioxide and water. The reactions are spontaneous and generate large amounts of energy.
  • 6. COMPLETE OXIDATION Glucose can be used by two pathways i.e. aerobic and anaerobic respiration. Glucose is completely oxidised only in the presence of oxygen and results in the release of energy. It undergoes three steps to finally reach its fate - glycolysis, Kreb's cycle and electron transport chain reaction. In anaerobic respiration, glucose undergoes partial oxidation and results in the release of energy which is comparitvely less to the energy released during aerobic respiration.
  • 7. WHERE IS GLUCOSE COMPLETELY OXIDIZED? Glycolysis only represents the first pathway involved in glucose oxidation. The remaining pathways involve the Krebs cycle and the electron transport chain, where the oxidation process is completed. Where is glucose completely oxidized? Glycolysis occurs within the cytoplasm of the cell. The products of glycolysis are then transported into the mitochondria, where the Krebs cycle and processing in the mitochondria take place.
  • 8. OXIDATION OF GLUCOSE There are two pathways for oxidation of Glucose. 1) Major pathways: Glycolysis. Kreb's cycle. 2) Minor pathway: Pentose shunt
  • 10. GLYCOLYSIS: ENERGY INVESTMENT In reactions 1 to 5 of glycolysis, energy is required to add phosphate groups to glucose. glucose is converted to two three-carbon molecules.
  • 11. GLYCOLYSIS: ENERGY GENERATING In reactions 6 to 10 of glycolysis, energy is obtained from the hydrolysis of the energy-rich phosphate compounds. four ATP are synthesized.
  • 12. GLYCOLYSIS: REACTION 1 In reaction 1, phosphorylation, a phosphate group is transferred from ATP to glucose. glucose-6-phosphate and ADP are produced. the enzyme hexokinase catalyzes the reaction.
  • 13. GLYCOLYSIS: REACTION 2 In reaction 2, isomerization, glucose-6-phosphate, the aldose from reaction 1, is converted to fructose-6-phosphate. the isomerization is catalyzed by the enzyme phosphoglucose isomerase.
  • 14. GLYCOLYSIS: REACTION 3 In reaction 3, phosphorylation, hydrolysis of another ATP provides a second phosphate group. the phosphate group is transferred to fructose-6-phosphate, producing fructose-1,6-bisphosphate. a second kinase enzyme called phosphofructokinase catalyzes the reaction.
  • 15. GLYCOLYSIS: REACTION 4 In reaction 4, cleavage, fructose-1,6-bisphosphate is split into two three-carbon phosphate isomers. the enzyme aldolase produces dihydroxyacetone phosphate and glyceraldehyde-3-phosphate.
  • 16. GLYCOLYSIS: REACTION 5 In reaction 5, isomerization, dihydroxyacetone phosphate undergoes isomerization catalyzed by triose phosphate isomerase. a second molecule of glyceraldehyde-3-phosphate is produced, which can be oxidized. all six carbon atoms from glucose are contained in two identical triose phosphates.
  • 17. GLYCOLYSIS: REACTION 6 In reaction 6, oxidation and phosphorylation, the aldehyde group of each glyceraldehyde-3-phosphate is oxidized to a carboxyl group. NAD+ is reduced to NADH and H+. a phosphate group is transferred to each of the new carboxyl groups, forming two molecules of 1,3-bisphosphoglycerate.
  • 18. GLYCOLYSIS: REACTION 7 In reaction 7, phosphate transfer, a phosphate group from each 1,3-bisphosphoglycerate is transferred to two ADP molecules by phosphoglycerate kinase. two molecules of the high-energy compound ATP are produced.
  • 19. GLYCOLYSIS: REACTION 8 In reaction 8, isomerization, two 3-phosphoglycerate molecules undergo isomerization by phosphoglycerate mutase. the phosphate group is moved from carbon 3 to carbon 2, yielding two molecules of 2-phosphoglycerate.
  • 20. GLYCOLYSIS: REACTION 9 In reaction 9, dehydration, each phosphoglycerate molecule undergoes dehydration by the enzyme enolase. two high-energy phosphoenolpyruvate molecules are produced.
  • 21. GLYCOLYSIS: REACTION 10 In reaction 10, phosphate transfer, phosphate groups from two phosphoenolpyruvate molecules are transferred by pyruvate kinase to yield two ADP, two pyruvate, and two ATP. a fourth kinase enzyme transfers a phosphate with ATP production.
  • 22. GLYCOLYSIS: OVERALL REACTION In glycolysis, two ATP add phosphate to glucose and fructose-6-phosphate. four ATP are formed in energy generation by direct transfers of phosphate groups to four ADP. there is a net gain of 2 ATP and 2 NADH.
  • 23. FRUCTOSE AND GALACTOSE Other monosaccharides, such as fructose and galactose, can enter glycolysis after they are converted to intermediates. In muscles and kidneys, fructose is phosphorylated to fructose-6-phosphate, which enters glycolysis in reaction 3. Galactose reacts with ATP to yield galactose-1-phosphate, which is converted to glucose-6- phosphate, which then enters glycolysis at reaction 2.
  • 24. FRUCTOSE AND GALACTOSE Galactose and fructose form intermediates that enter the glycolysis pathway to be metabolized.
  • 25. REGULATION OF GLYCOLYSIS Glycolysis is regulated by three enzymes. In reaction 1, hexokinase is inhibited by high levels of glucose-6-phosphate, which prevents the phosphorylation of glucose. In reaction 3, phosphofructokinase, an allosteric enzyme, is inhibited by high levels of ATP and activated by high levels of ADP and AMP. In reaction 10, pyruvate kinase, another allosteric enzyme, is inhibited by high levels of ATP or acetyl CoA.
  • 26. IMPORTANCE OF GLYCOLYSIS Nearly all of the energy used by living cells comes from the energy in the bonds of the sugar glucose. Glycolysis is the first pathway used in the breakdown of glucose to extract energy. It takes place in the cytoplasm of both prokaryotic and eukaryotic cells. It was probably one of the earlier metabolic pathways to evolve since it is used by nearly all of the organisms on earth.
  • 27. IMPORTANCE OF GLYCOLYSIS The process doesnt use oxygen and is, therefore, anaerobic. Glycolysis is the first of the main metabolic pathways of cellular respiration to produce energy in the form of ATP. Overall, the process of glycolysis produces a net gain of two pyruvate molecules, two ATP molecules, and two NADH molecules for the cell to use for energy.
  • 28. KREB'S CYCLE The Krebs cycle or TCA cycle (tricarboxylic acid cycle) or Citric acid cycle is a series of enzyme catalysed reactions occurring in the mitochondrial matrix, where acetyl-CoA is oxidised to form carbon dioxide and coenzymes are reduced, which generate ATP in the electron transport chain.
  • 30. KREB'S CYCLE STEPS After glycolysis, in aerobic organisms, the pyruvate molecules are carboxylated to form acetyl CoA and CO2. Oxidative Decarboxylation of pyruvate to Acetyl CoA
  • 31. STEP 1: CONDENSATION OF ACETYL COA WITH OXALOACETATE The first step of the citric acid cycle is the joining of the four-carbon compound oxaloacetate (OAA) and a two-carbon compound acetyl CoA. The oxaloacetate reacts with the acetyl group of the acetyl CoA and water, resulting in the formation of a six-carbon compound citric acid, CoA.
  • 32. STEP 2: ISOMERIZATION OF CITRATE INTO ISOCITRATE Now, for further metabolism, citrate is converted into isocitrate through the formation of intermediate cis- aconitase. This reaction is a reversible reaction catalyzed by the enzyme aconitase.
  • 33. STEP 3: OXIDATIVE DECARBOXYLATIONS OF ISOCITRATE The third step of the citric acid cycle is the first of the four oxidation-reduction reactions in this cycle. Isocitrate is oxidatively decarboxylated to form a five-carbon compound, 留-ketoglutarate catalyzed by the enzyme isocitrate dehydrogenase. This reaction, like the second reaction, is a two-step reaction.
  • 34. STEP 4: OXIDATIVE DECARBOXYLATION OF - KETOGLUTARATE This step is another one of the oxidation-reduction reactions where 留- ketoglutarate is oxidatively decarboxylated to form a four-carbon compound, succinyl-CoA, and CO2.
  • 35. STEP 5: CONVERSION OF SUCCINYL-COA INTO SUCCINATE In the next step, succinyl-CoA undergoes an energy-conserving reaction in which succinyl-CoA is cleaved to form succinate. This reaction is accompanied by phosphorylation of guanosine diphosphate (GDP) to guanosine triphosphate (GTP).
  • 36. STEP 6: DEHYDRATION OF SUCCINATE TO FUMARATE Here, the succinate formed from succinyl-CoA is dehydrogenated to fumarate catalyzed by the enzyme complex succinate dehydrogenase found in the intramitochondrial space.
  • 37. STEP 7: HYDRATION OF FUMARATE TO MALATE The fumarate is reversibly hydrated to form L-malate in the presence of the enzyme fumarate hydratase.
  • 38. STEP 8: DEHYDROGENATION OF L-MALATE TO OXALOACETATE The last step of the citric acid cycle is also an oxidation-reduction reaction where L-malate is dehydrogenated to oxaloacetate in the presence of L-malate dehydrogenase, which is present in the mitochondrial matrix.
  • 39. IMPORTANCE OF KREBS CYCLE The Krebs cycle is the second of three stages of cellular respiration, in which glucose, fatty acids and certain amino acids, the so-called fuel molecules, are oxidized (see Figure). The oxidation of these molecules is primarily used to transform the energy contained in these molecules into ATP. ATP provides for example energy for muscle contractions and can therefore be referred to as "energy currency" of the cells. The Krebs cycle has two important functions. One is production of intermediate compounds important in the synthesis of substances such as amino and fatty acids. The other is formation of large quantities of ATP that provides energy for various synthetic processes.
AboutCopyright
息 2025 際際滷