respiratory pigments

Respiratory pigments are molecules found in the blood or tissues that help transport oxygen from the lungs or gills to the body's cells and carry carbon dioxide back for removal. They contain a metal atom, usually iron or copper, at their core, which binds oxygen molecules efficiently. Hemoglobin, the most common respiratory pigment in mammals, gives blood its red color. Other animals, like some invertebrates and marine creatures, use different pigments such as hemocyanin (blue) or hemerythrin (pink). These pigments are essential for supporting cellular respiration and energy production.