What is the red pigment in blood cells responsible for carrying oxygen?

Hemoglobin is the red pigment found in red blood cells and is essential for the transportation of oxygen throughout the body. It functions by binding to oxygen molecules in the lungs and releasing them in tissues that need oxygen for cellular respiration. Structurally, hemoglobin is a protein made up of four subunits, each containing a heme group that includes iron, which is crucial for oxygen binding.

Myoglobin, the other protein listed, is similar in function but primarily found in muscle cells where it serves to store oxygen rather than transport it in the bloodstream. Chlorophyll is a pigment involved in photosynthesis in plants, while carotene is a pigment found in various fruits and vegetables, responsible for their orange and yellow colors. These pigments do not play a role in oxygen transport in blood cells.