Vapaarasvahapot

Vapaarasvahapot, often abbreviated as FFAs or NEFAs (non-esterified fatty acids), are fatty acids that are not esterified, meaning they are not attached to a glycerol molecule or another alcohol. In biological systems, they are typically found circulating in the bloodstream. These molecules are crucial in cellular metabolism, serving as a primary energy source for many tissues, including muscles and the heart, especially during fasting or prolonged exercise when glucose levels are low.

The release of free fatty acids from adipose tissue (fat cells) is a process called lipolysis, which is stimulated by hormones like glucagon and adrenaline. Once released into the circulation, FFAs bind to albumin, a protein in the blood, for transport to various organs. In these organs, FFAs are taken up by cells and undergo beta-oxidation, a metabolic pathway that breaks them down into acetyl-CoA. Acetyl-CoA then enters the citric acid cycle to generate ATP, the energy currency of the cell.

While FFAs are vital for energy production, elevated levels in the blood, known as lipotoxicity, can be detrimental. Chronic high levels of FFAs are associated with insulin resistance, impaired pancreatic beta-cell function, and an increased risk of developing type 2 diabetes and cardiovascular diseases. Therefore, the regulation of FFA metabolism is tightly controlled by hormonal signals and cellular mechanisms to maintain metabolic homeostasis.