Glycolyysissä

Glycolyysissä is a Finnish term referring to glycolysis, a fundamental metabolic pathway that occurs in the cytoplasm of virtually all living cells. This process breaks down glucose, a six-carbon sugar, into two molecules of pyruvate, a three-carbon compound. Glycolysis is an anaerobic process, meaning it does not require oxygen to proceed.

The pathway involves a series of ten enzymatic reactions. The initial steps are energy-investing, where ATP is consumed to prime the glucose molecule for cleavage. Following this, the molecule is split, and subsequent steps are energy-yielding, generating ATP through substrate-level phosphorylation. In total, glycolysis yields a net gain of two ATP molecules and two NADH molecules for each molecule of glucose metabolized.

The pyruvate produced can then enter different metabolic fates depending on the availability of oxygen. Under aerobic conditions, pyruvate is further oxidized in the mitochondria through the Krebs cycle and oxidative phosphorylation, yielding a much larger amount of ATP. In the absence of oxygen (anaerobic conditions), pyruvate is converted into other end products, such as lactate in animals and ethanol in yeast, through fermentation. This fermentation process regenerates NAD+, which is essential for glycolysis to continue. Glycolysis is a crucial source of energy for cells, especially under anaerobic conditions, and it serves as a central hub connecting carbohydrate metabolism with other metabolic pathways.