Glycolysis is a metabolic process that converts glucose into pyruvate to provide energy for cells. It involves ten steps and produces ATP and NADH. Dysfunctional glycolysis can occur in cancer and Alzheimer’s disease.
Glycolysis is a complex biological process that occurs to convert glucose into pyruvate in order to provide energy for every living cell. Since the glycolysis cycle involves the conversion of blood sugar into a pyruvic acid (pyruvate) anion, glycolysis is also called the citric acid cycle.
Since this event also involves the release of free energy, it is considered a thermodynamic reaction. The end result is reduced synthesis of adenosine-5′-triphosphate (ATP) and nicotinamide adenine dinucleotide (NADH), two nucleotides that are key components of DNA and important for proper metabolic functioning. While glycolysis is a simple example of anaerobic cellular respiration and fermentation, there are ten reactive steps that occur involving several catalysing enzymes and intermediate compounds.
The first event that occurs in glycolysis uses the energy provided by glycolysis hexokinase enzymes to convert a sugar molecule (glucose) with six carbon atoms into two compounds containing three carbon atoms, or glucose 6-phosphate. This substance then undergoes a molecular rearrangement into “lactate” or produces a lactic acid anion. The “payback” for the energy expenditure in the initial phase of glycolysis is the subsequent production of two nicotinamide adenine dinucleotides (NAD), followed by a phosphate group which binds to each molecule of 3 carbon atoms, generating 1,3- bisphosphoglycerate. Meanwhile, the hydrogen in the reaction is used to reduce NAD, producing NADH. Finally, the enzyme glycolysis pyruvate kinase is used to produce two ATP for each glucose molecule involved in the glycolytic reaction.
Glycolysis is a basic metabolic pathway that probably evolved billions of years ago. However, while it occurs in nearly all living organisms, it does so with variations. For example, although glucose is the usual stepping stone to initiate glycolysis, other monosaccharides can be introduced into the reaction. Furthermore, lactate is not the only possible byproduct of glycolysis, as evidenced by the production of carbon dioxide and ethanol when brewer’s yeast undergoes fermentation. Finally, not all carbon is necessarily converted to pyruvate and can be used to promote other carbon-related pathways.
Dysfunctional glycolysis also occurs. For example, cancer cells often have a glycolytic cycle up to 200 times higher than that of normal cells. Known as the Warburg effect, this acceleration can occur due to an abundance of hexokinase enzymes or a lack of oxygen due to lack of blood flow to the site. A similar disturbance in glucose metabolism is observed in Alzheimer’s disease. However, this is more likely caused by a buildup of specific proteins that interfere with phosphorylation.
Protect your devices with Threat Protection by NordVPN
