What is the specialized respiratory pigment found in the blood of many invertebrates such as molluscs and crustaceans that contains copper and imparts a blue color to their blood upon oxygenation?

💡 Solution & Explanation

Hemocyanin is a copper-containing respiratory metalloprotein found freely dissolved in the hemolymph of arthropods and molluscs, turning blue when oxygenated. Hemoglobin is an iron-containing protein found in vertebrate erythrocytes, while myoglobin stores oxygen within vertebrate muscle tissue. Cytochrome c functions in the mitochondrial electron transport chain for cellular respiration. Copper binding sites in hemocyanin facilitate reversible oxygen binding.