Koenzýmy

Koenzýmy are organic, non-protein molecules that bind to enzymes and are required for their activity. They act as transient carriers of specific chemical groups, atoms, or electrons, facilitating various biochemical reactions within cells. Unlike prosthetic groups, which are permanently bound to an enzyme, coenzymes are typically loosely associated and can be released from the enzyme's active site after the reaction is complete. This allows a single coenzyme molecule to participate in multiple catalytic cycles with different enzymes.

The majority of coenzymes are derived from vitamins, essential nutrients that the body cannot synthesize on its own. For example, nicotinamide adenine dinucleotide (NAD+) and nicotinamide adenine dinucleotide phosphate (NADP+) are derived from niacin (vitamin B3) and are crucial for redox reactions, transferring electrons. Flavin adenine dinucleotide (FAD) and flavin mononucleotide (FMN), derived from riboflavin (vitamin B2), also play vital roles in electron transport. Coenzyme A (CoA), derived from pantothenic acid (vitamin B5), is essential for the transfer of acyl groups, notably in the metabolism of carbohydrates, fats, and proteins.

Other important coenzymes include thiamine pyrophosphate (TPP) from thiamine (vitamin B1), pyridoxal phosphate (PLP) from pyridoxine (vitamin B6), biotin (vitamin B7), and cobalamin (vitamin B12). Each coenzyme has a specific role in a particular type of chemical transformation. Their efficient function is critical for a vast array of metabolic processes, including energy production, synthesis of biomolecules, and detoxification. Deficiencies in vitamins that serve as precursors to coenzymes can therefore lead to significant metabolic disruptions and associated health problems.