koensüümidena

Koensüümidena is the Estonian term for coenzymes. Coenzymes are small organic non-protein molecules that are required for the activity of many enzymes. They bind to enzymes and are essential for their catalytic function, though they are not consumed in the reaction. Coenzymes can be divided into two main groups: those that are derived from vitamins and those that are not.

Vitamin-derived coenzymes are crucial for a vast array of metabolic processes within living organisms. For instance, NAD+ (nicotinamide adenine dinucleotide) and NADP+ (nicotinamide adenine dinucleotide phosphate), derived from niacin (vitamin B3), are essential for redox reactions, playing roles in energy production and biosynthesis. FAD (flavin adenine dinucleotide), derived from riboflavin (vitamin B2), is another vital coenzyme involved in electron transport chains and metabolic pathways. Thiamine pyrophosphate (TPP), derived from thiamine (vitamin B1), is critical for carbohydrate metabolism, participating in decarboxylation reactions. Coenzyme A (CoA), derived from pantothenic acid (vitamin B5), is central to fatty acid metabolism and the citric acid cycle. Pyridoxal phosphate (PLP), derived from vitamin B6, is a coenzyme for many enzymes involved in amino acid metabolism. Biotin (vitamin B7) acts as a coenzyme for carboxylase enzymes, involved in the synthesis of fatty acids and glucose. Finally, cobalamin (vitamin B12) serves as a coenzyme in various enzymatic reactions, including DNA synthesis and fatty acid metabolism.

Non-vitamin-derived coenzymes include molecules like ATP (adenosine triphosphate), although often considered an energy currency, it functions as a coenzyme in many phosphorylation reactions. Other examples include heme, which acts as a coenzyme for cytochromes involved in electron transport, and tetrahydrobiopterin (BH4), essential for the synthesis of neurotransmitters and nitric oxide. The efficient functioning of cells and metabolism relies heavily on the proper availability and activity of these vital coenzymes.