Flavoproteins are a group of proteins that contain a flavin molecule, which is derived from vitamin B2 (riboflavin). These proteins play essential roles in various biological processes, including cellular respiration and metabolism. They are involved in redox reactions, helping to transfer electrons in biochemical pathways. Flavoproteins are found in many organisms, from bacteria to humans, and are crucial for the function of enzymes. They can be classified into different types based on their specific functions, such as flavoprotein oxidases and flavoprotein dehydrogenases. Their diverse roles make them important for maintaining cellular health and energy production.