Which intermediate in the oxidation of glucose

The pyruvic acid diffuses into the inner compartment of the mitochondrion where a transition reaction Fig. The above notes describe the process of carbohydrate glucose catabolism for the production of ATP. When glucose is in adequate supply, such as shortly after consumption of a meal, the hormone insulin from the pancreas increases glycogen formation glycogenesis in the liver.

When glucose levels drop between meals, the hormone glucagon is released from the pancreas and stimulates the conversion of glycogen into glucose by the process of glycogenolysis. If all glycogen supplies are depleted, then other substances in the body are converted into glucose or intermediate products that can enter the above-outlined cellular respiration pathway.

The conversion of fatty acids from lipids or amino acids from proteins into glucose or intermediate products is called gluconeogenesis p. Fats lipids are stored in adipose tissue.

Something went wrong. Try again? Cited by. Download options Please wait Supplementary information PDF K. Article type Paper. Submitted 17 Feb Accepted 03 May First published 04 May Download Citation. Green Chem. Request permissions. Pt catalysts for efficient aerobic oxidation of glucose to glucaric acid in water J. This intermediate, which is stable, is released with low frequency by the enzyme instead of being converted to 2-PG.

Thus, cells which are metabolizing glucose rapidly release more 2,3BPG and, as a result, stimulate release of more oxygen, supporting their needs. Consequently, the energy is lost as heat. If you wonder why you get hot when you exercise, the reaction that converts PEP to pyruvate is a prime culprit. Control of glycolysis is unusual for a metabolic pathway, in that regulation occurs at three enzymatic points:.

Glycolysis is regulated in a reciprocal fashion compared to its corresponding anabolic pathway, gluconeogenesis. Reciprocal regulation occurs when the same molecule or treatment phosphorylation, for example has opposite effects on catabolic and anabolic pathways.

Reciprocal regulation is important when anabolic and corresponding catabolic pathways are occurring in the same cellular location.

As an example, consider regulation of PFK. It is activated by several molecules, most importantly fructose-2,6- bisphosphate F2,6BP. This molecule has an inhibitory effect on the corresponding gluconeogenesis enzyme, fructose-1,6-bisphosphatase F1,6BPase. You might wonder why pyruvate kinase, the last enzyme in the pathway, is regulated. The answer is simple. Pyruvate kinase catalyzes the most energetically rich reaction of glycolysis. In other words, it takes two enzymes, two reactions, and two triphosphates to go from pyruvate back to PEP in gluconeogenesis.

Another interesting control mechanism called feedforward activation involves pyruvate kinase.