sitruunahappokiertoihin

Sitruunahappokiertoihin, or the citric acid cycle, also known as the Krebs cycle or TCA cycle, is a fundamental metabolic pathway that occurs in the mitochondria of aerobic organisms. It is a central part of cellular respiration, playing a key role in the breakdown of carbohydrates, fats, and proteins to generate energy in the form of ATP. The cycle begins with acetyl-CoA, a molecule derived from the breakdown of food. Acetyl-CoA combines with oxaloacetate to form citrate, a six-carbon molecule. Through a series of enzymatic reactions, citrate is progressively oxidized, releasing carbon dioxide as a byproduct. During these reactions, high-energy electron carriers, NADH and FADH2, are produced. These molecules then proceed to the electron transport chain, where their energy is used to synthesize a large amount of ATP. The citric acid cycle also generates precursor molecules for various biosynthetic pathways, such as the synthesis of amino acids and heme. It is a highly regulated process, ensuring that energy production is balanced with the cell's needs. The cycle's interconnectedness with other metabolic pathways highlights its importance in maintaining cellular homeostasis and overall organismal health.