Flavoproteins are a group of proteins that contain a flavin molecule, which is derived from vitamins such as riboflavin (vitamin B2). These proteins play essential roles in various biological processes, including cellular respiration and photosynthesis. They are involved in redox reactions, helping to transfer electrons and facilitate energy production in cells. 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, each contributing to metabolic pathways and overall cellular health.