Glycolysis: Not a Mitochondrial Function
The metabolic activity of Glycolysis takes places outside the mitochondria in the cytoplasm. The glycolytic process is used to obtain energy for the cell. It is an anaerobic oxidative process. There are two main processes in glycolysis. The first process is an "Activation and Cleavage."
Activation and Cleavage
The purpose of the four steps in phase one is to activate glucose to a level that enzymes can control the rate of the reaction. It will take the energy of two ATPs to activate glucose. Once glucose is activated it breaks (cleaves) into two three-carbon compounds. Each step is controlled by a specific enzyme. Step four's two compounds are isomers. One of the carbon compounds produced in step four (dihydroxyacetone phosphate) is converted into the other product (glyceraldehyde-3-phosphate) by step five process.
Step One
Partial activation of glucose by ATP to glucose-6-phosphateStep Two
Transformation of glucose-6-phosphate to fructose-6-phosphateStep Three
Activation of fructose-6-phosphate by ATP to fructose-1,6-biphosphateStep Four
Cleavage of fructose-1,6-biphosphate to dihydroxyacetone phosphate and glyceraldehyde-3-phosphateStep Five (Transition Step)
Conversion of dihydroxyacetone phosphate to glyceraldehyde-3-phosphateWhole Process
Watch steps one through five in as a complete process of activation and cleavage.
The second process contains the main energy reactions that involve oxidation, ATP generation, and pyruvate formation.
Oxidation, ATP Generation and Pyruvate Formation
In steps six through ten, two main processes occur to the two molecules produced in steps 1-5. First, there is an oxidation of glyceraldehyde-3-phosphate releasing an electron. The product of this reaction, 1,3-bisphosphoglycerate, then produces an ATP. The second main process is the production of pyruvate (used in the TCA cycle) and an ATP from phosphoenol-pyruvate. The energy to drive these reaction was acquired in the first four steps.
The reactions given below will only show one molecule going through each of the steps. Keep in mind that the second molecule also goes through each of these steps as well.
Step Six
Oxidation of Glyceraldehyde-3-Phosphate to 1,3-bisphosphogylcerateStep Seven
ATP generation by 1,3-bisphosphoglycerate conversion to 3-phosphogylcerateStep Eight
Transformation of 3-phosphoglycerate to 2-phosphoglycerateStep Nine
Transformation of 2-phosphoglycerate to PhosphenolpyruvateStep Ten
Pyruvate production from PhosphenolpyruvateWhole Process
Steps six through ten, oxidation and pyruvate formation, are demonstrated without stopping.
If the glycolytic process is the terminal process of energy acquisition, then the electrons obtained in the process are passed back to pyruvate forming other products. These processes are generally called Fermentation.
If you want to view the whole process, after viewing both main processes, just click here.
