kataboliset

Kataboliset, from the Finnish term kataboliset prosessit, describes catabolic metabolic pathways that break down complex molecules into simpler ones, releasing energy in the process. In biology, catabolism is contrasted with anabolism, the set of pathways that build complex molecules from smaller ones. Together they form the total metabolism of an organism.

In cellular metabolism, catabolic reactions harvest energy by oxidizing substrates such as carbohydrates, fats, and proteins. The energy released is captured in molecules like ATP, NADH, and FADH2, which feed into energy-conserving processes such as oxidative phosphorylation. Catabolic pathways also provide building blocks for biosynthesis and maintenance of cellular components through their degradation products.

Key catabolic routes include glycolysis (glucose to pyruvate), the breakdown of fatty acids via beta-oxidation to acetyl-CoA, and the citric acid cycle, which together extract energy from carbohydrates and fats. Proteolysis and autophagy degrade proteins and organelles to recycle amino acids and other components. In anaerobic conditions, fermentation can also serve a catabolic purpose by generating energy when respiration is limited.

Regulation of catabolic activity is tightly linked to the organism’s energy status and hormonal environment. Hormones such as glucagon, epinephrine, and cortisol promote catabolic processes, especially during fasting or stress, whereas insulin tends to suppress them. Energy-sensing mechanisms, notably AMP-activated protein kinase (AMPK), activate catabolic pathways when energy is scarce, while mammalian target of rapamycin (mTOR) promotes anabolic processes under nutrient-rich conditions.

Kataboliset processes are essential for providing energy during fasting, exercise, and stress, and play a role in health and disease, including conditions characterized by excessive or chronic muscle and tissue breakdown.