Energetics of glycolysis

© 2010 Cells, like humans, cannot generate energy without locating a source in their environment. However, whereas humans search for substances like fossil fuels to power their homes and businesses, cells seek their energy in the form of food molecules or sunlight. In fact, the Sun is the ultimate source of energy for almost all cells, because photosynthetic prokaryotes, algae, and plant cells harness solar energy and use it to make the complex organic food molecules that other cells rely on for the energy required to sustain growth, metabolism, and reproduction (Figure 1). Cellular nutrients come in many forms, including sugars and fats. In order to provide a cell with energy, these molecules have to pass across the cell membrane, which functions as a barrier — but not an impassable one. Like the exterior walls of a house, the plasma membrane is semi-permeable. In much the same way that doors and windows allow necessities to enter the house, various proteins that span the cell membrane permit specific molecules into the cell, although they may require some energy input to accomplish this task (Figure 2). This amoeba, a single-celled organism, acquires energy by engulfing nutrients in the form of a yeast cell (red). Through a process called phagocytosis, the amoeba encloses the yeast cell with its membrane and draws it inside. Specialized plasma membrane proteins in the amoeba (in green) are involved in this act of phagocytosis, and they are later recycled back into the am...

Examinations • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • Energetics of Anaerobic Glycolysis Introduction One glucose molecule is broken down into two pyruvate molecules during the glycolysis process. Pyruvate has different fates depending on the microcellular environment (particularly, energy demand, oxygen availability, and the presence or absence of mitochondria). Pyruvate can enter the citric acid cycle within the matrix of mitochondria and undergo oxidative phosphorylation in mitochondria-containing cells. Pyruvate remains within the cytoplasm of erythrocytes and oxygen-depleted tissue, where it transforms to lactate via anaerobic glycolysis. This final step allows for the regeneration of NAD+, a cofactor that must be present in sufficient intracellular concentrations for the earlier glycolysis events to function properly. On the other hand, Anaerobic glycolysis is substantially less efficient than oxidative phosphorylation, producing only 2 ATP per glucose molecule (versus 32 ATP per glucose molecule produced during oxidative phosphorylation). Table of Contents • • • • Overview of Glycolysis Glycolysis is the process of breaking down glucose into pyruvate within a cell’s cytoplasm. Pyruvate can diffuse into m...

• From glucose, two molecules of glyceraldehyde 3-phosphate are formed in the second stage of • Hence energetic of Energetics of Stages/steps Enzyme Method of high energy bond formation No. of Formed ATP Formation of 1,3-bisphospho glycerate from glyceraldehydes 3-phosphate Glyceraldehyde 3-phosphate dehydrogenase Respiratory chain oxidation of 2 NADH 5 Stage 2 Formation of 3 phosphoglycerate from 1,3 bisphospho glycerate Phosphoglycerate kinase Phosphorylation at subtrate level 2 Stage 3 Formation of pyruvate from phosphoenol pyruvate Pyruvate kinase Phosphorylation at subrate level 2 Allowance for consumption of ATP by reactions catalysed Hexokinase and phosphor fructose kinase 2 Number of ATP molecules enerated by catabolism of one molecule of glucose under aerobic conditions 7 Number of ATP molecules generated by the catabolism of one molecule of glucose under anaerobic conditions 2 • • Site pages • Tags • Calendar • Site news • Current course • • Participants • General • Topic 1 • Topic 2 • Topic 3 • Topic 4 • Topic 5 • Topic 6 • Topic 7 • Topic 8 • Topic 9 • Topic 10 • Topic 11 • Topic 12 • Topic 13 • Topic 14 • Topic 15 • Topic 16 • Introduction • Metabolic processes in carbohydrates • Glycolysis • Energetics of glycolysis • Significance of glycolysis • Quiz • Topic 17 • Topic 18 • Topic 19 • Topic 20 • Topic 21 • Topic 22 • Topic 23 • Topic 24 • Topic 25 • Topic 26 • Topic 27 • Topic 28 • Topic 29 • Topic 30 • Topic 31 • Topic 32 • Topic 33 • Topic 34 • Topic 35 •

• From glucose, two molecules of glyceraldehyde 3-phosphate are formed in the second stage of • Hence energetic of Energetics of Stages/steps Enzyme Method of high energy bond formation No. of Formed ATP Formation of 1,3-bisphospho glycerate from glyceraldehydes 3-phosphate Glyceraldehyde 3-phosphate dehydrogenase Respiratory chain oxidation of 2 NADH 5 Stage 2 Formation of 3 phosphoglycerate from 1,3 bisphospho glycerate Phosphoglycerate kinase Phosphorylation at subtrate level 2 Stage 3 Formation of pyruvate from phosphoenol pyruvate Pyruvate kinase Phosphorylation at subrate level 2 Allowance for consumption of ATP by reactions catalysed Hexokinase and phosphor fructose kinase 2 Number of ATP molecules enerated by catabolism of one molecule of glucose under aerobic conditions 7 Number of ATP molecules generated by the catabolism of one molecule of glucose under anaerobic conditions 2 • • Site pages • Tags • Calendar • Site news • Current course • • Participants • General • Topic 1 • Topic 2 • Topic 3 • Topic 4 • Topic 5 • Topic 6 • Topic 7 • Topic 8 • Topic 9 • Topic 10 • Topic 11 • Topic 12 • Topic 13 • Topic 14 • Topic 15 • Topic 16 • Introduction • Metabolic processes in carbohydrates • Glycolysis • Energetics of glycolysis • Significance of glycolysis • Quiz • Topic 17 • Topic 18 • Topic 19 • Topic 20 • Topic 21 • Topic 22 • Topic 23 • Topic 24 • Topic 25 • Topic 26 • Topic 27 • Topic 28 • Topic 29 • Topic 30 • Topic 31 • Topic 32 • Topic 33 • Topic 34 • Topic 35 •

Examinations • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • Energetics of Anaerobic Glycolysis Introduction One glucose molecule is broken down into two pyruvate molecules during the glycolysis process. Pyruvate has different fates depending on the microcellular environment (particularly, energy demand, oxygen availability, and the presence or absence of mitochondria). Pyruvate can enter the citric acid cycle within the matrix of mitochondria and undergo oxidative phosphorylation in mitochondria-containing cells. Pyruvate remains within the cytoplasm of erythrocytes and oxygen-depleted tissue, where it transforms to lactate via anaerobic glycolysis. This final step allows for the regeneration of NAD+, a cofactor that must be present in sufficient intracellular concentrations for the earlier glycolysis events to function properly. On the other hand, Anaerobic glycolysis is substantially less efficient than oxidative phosphorylation, producing only 2 ATP per glucose molecule (versus 32 ATP per glucose molecule produced during oxidative phosphorylation). Table of Contents • • • • Overview of Glycolysis Glycolysis is the process of breaking down glucose into pyruvate within a cell’s cytoplasm. Pyruvate can diffuse into m...

Yes, Glycolysis has already made a 2 net gain of ATP, and in aerobic environment (oxygen is around) theses ATP would then move to the Krebs cycle, and the Electron Transport Chain to supply 36 ATP, however then the body is starved oxygen (anaerobic respiration) the 2 ATP produced on Glycolysis is not enough energy to supply the body with the need energy, so it enters a sage of Fermentation (production of lactic acid in animals, and ethanol in plants). Fermentation then continually uses the ATP from glycolysis and turns it into 2 Pyruvate, by using 2NAD+ and turning it into 2 NADH and 2 H+ and the energy from the ATP, forming Lactic acid ( which is why a muscles fell stiff after exercising). The thing is that it can keep using the 'same' ATP to continually make 2 ATP, which glycolysis could not... as it needed oxygen present. Hope that helped a bit... :) Look, in real life, you have to build something and to do some investment - in your studies, in your job, if building a house, in creating a masterpiece if the cooking meal or investing in your spiritual health. So, the cell as well has to invest little ATP in order to let glycolysis happen. Glycolysis is not a spontaneous process and requires energy. Any kind of work in a cell is active and requires energy - in the form of ATP. Glycolysis is not a spontaneous process. So I see we're generating ATP, which are the currency of energy and then, as electrons move to lower energy states, they release energy. We talk about genera...

© 2010 Cells, like humans, cannot generate energy without locating a source in their environment. However, whereas humans search for substances like fossil fuels to power their homes and businesses, cells seek their energy in the form of food molecules or sunlight. In fact, the Sun is the ultimate source of energy for almost all cells, because photosynthetic prokaryotes, algae, and plant cells harness solar energy and use it to make the complex organic food molecules that other cells rely on for the energy required to sustain growth, metabolism, and reproduction (Figure 1). Cellular nutrients come in many forms, including sugars and fats. In order to provide a cell with energy, these molecules have to pass across the cell membrane, which functions as a barrier — but not an impassable one. Like the exterior walls of a house, the plasma membrane is semi-permeable. In much the same way that doors and windows allow necessities to enter the house, various proteins that span the cell membrane permit specific molecules into the cell, although they may require some energy input to accomplish this task (Figure 2). This amoeba, a single-celled organism, acquires energy by engulfing nutrients in the form of a yeast cell (red). Through a process called phagocytosis, the amoeba encloses the yeast cell with its membrane and draws it inside. Specialized plasma membrane proteins in the amoeba (in green) are involved in this act of phagocytosis, and they are later recycled back into the am...

© 2010 Cells, like humans, cannot generate energy without locating a source in their environment. However, whereas humans search for substances like fossil fuels to power their homes and businesses, cells seek their energy in the form of food molecules or sunlight. In fact, the Sun is the ultimate source of energy for almost all cells, because photosynthetic prokaryotes, algae, and plant cells harness solar energy and use it to make the complex organic food molecules that other cells rely on for the energy required to sustain growth, metabolism, and reproduction (Figure 1). Cellular nutrients come in many forms, including sugars and fats. In order to provide a cell with energy, these molecules have to pass across the cell membrane, which functions as a barrier — but not an impassable one. Like the exterior walls of a house, the plasma membrane is semi-permeable. In much the same way that doors and windows allow necessities to enter the house, various proteins that span the cell membrane permit specific molecules into the cell, although they may require some energy input to accomplish this task (Figure 2). This amoeba, a single-celled organism, acquires energy by engulfing nutrients in the form of a yeast cell (red). Through a process called phagocytosis, the amoeba encloses the yeast cell with its membrane and draws it inside. Specialized plasma membrane proteins in the amoeba (in green) are involved in this act of phagocytosis, and they are later recycled back into the am...

Examinations • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • Energetics of Anaerobic Glycolysis Introduction One glucose molecule is broken down into two pyruvate molecules during the glycolysis process. Pyruvate has different fates depending on the microcellular environment (particularly, energy demand, oxygen availability, and the presence or absence of mitochondria). Pyruvate can enter the citric acid cycle within the matrix of mitochondria and undergo oxidative phosphorylation in mitochondria-containing cells. Pyruvate remains within the cytoplasm of erythrocytes and oxygen-depleted tissue, where it transforms to lactate via anaerobic glycolysis. This final step allows for the regeneration of NAD+, a cofactor that must be present in sufficient intracellular concentrations for the earlier glycolysis events to function properly. On the other hand, Anaerobic glycolysis is substantially less efficient than oxidative phosphorylation, producing only 2 ATP per glucose molecule (versus 32 ATP per glucose molecule produced during oxidative phosphorylation). Table of Contents • • • • Overview of Glycolysis Glycolysis is the process of breaking down glucose into pyruvate within a cell’s cytoplasm. Pyruvate can diffuse into m...

• From glucose, two molecules of glyceraldehyde 3-phosphate are formed in the second stage of • Hence energetic of Energetics of Stages/steps Enzyme Method of high energy bond formation No. of Formed ATP Formation of 1,3-bisphospho glycerate from glyceraldehydes 3-phosphate Glyceraldehyde 3-phosphate dehydrogenase Respiratory chain oxidation of 2 NADH 5 Stage 2 Formation of 3 phosphoglycerate from 1,3 bisphospho glycerate Phosphoglycerate kinase Phosphorylation at subtrate level 2 Stage 3 Formation of pyruvate from phosphoenol pyruvate Pyruvate kinase Phosphorylation at subrate level 2 Allowance for consumption of ATP by reactions catalysed Hexokinase and phosphor fructose kinase 2 Number of ATP molecules enerated by catabolism of one molecule of glucose under aerobic conditions 7 Number of ATP molecules generated by the catabolism of one molecule of glucose under anaerobic conditions 2 • • Site pages • Tags • Calendar • Site news • Current course • • Participants • General • Topic 1 • Topic 2 • Topic 3 • Topic 4 • Topic 5 • Topic 6 • Topic 7 • Topic 8 • Topic 9 • Topic 10 • Topic 11 • Topic 12 • Topic 13 • Topic 14 • Topic 15 • Topic 16 • Introduction • Metabolic processes in carbohydrates • Glycolysis • Energetics of glycolysis • Significance of glycolysis • Quiz • Topic 17 • Topic 18 • Topic 19 • Topic 20 • Topic 21 • Topic 22 • Topic 23 • Topic 24 • Topic 25 • Topic 26 • Topic 27 • Topic 28 • Topic 29 • Topic 30 • Topic 31 • Topic 32 • Topic 33 • Topic 34 • Topic 35 •