血紅蛋白、肌紅蛋白與胎兒血紅素

Hemoglobin is an iron-containing protein in the blood of many animals. This protein is in the red blood cells of vertebrates that transports oxygen to the tissues. Hemoglobin forms an unstable, reversible bond with oxygen; in the oxygenated state it is called oxyhemoglobin and is bright red; in the reduced state it is purplish blue.

Myoglobin is a protein found in the muscle cells of animals. It functions as an oxygen-storage unit, providing oxygen to the working muscles...In contact with venous blood (not blood in capillaries?), oxygen combines more readily with myoglobin than it does with hemoglobin, favoring the transfer of oxygen from blood to muscle cells.

Information modified from britannica.com

The term ‘red meat’ encompasses beef, veal, pork, lamb and mutton. A high concentration of myoglobin in this type of meat, which in contact with oxygen transforms to reddish oxymyoglobin,

makes myoglobin-rich meats appear red.

Wolk, A. (2017). Potential health hazards of eating red meat. J Intern Med 281: 106-122. Retrieved from https://onlinelibrary.wiley.com/doi/pdf/10.1111/joim.12543

Image from: brainkart.com