Porphyrins are organic compounds characterized by their large, ring-like structures made up of carbon, nitrogen, and hydrogen atoms. They play a crucial role in various biological processes, particularly in the formation of hemoglobin, the protein in red blood cells that carries oxygen. Porphyrins can also be found in chlorophyll, the green pigment in plants that is essential for photosynthesis. These compounds are important in medicine and biochemistry, as they can be involved in the synthesis of vital molecules and serve as indicators of certain diseases. Abnormal levels of porphyrins in the body can lead to conditions known as porphyrias, which can affect the skin and nervous system.