What is the name of the red pigment in blood cells that carries oxygen?

Hemoglobin is the primary red pigment found in blood cells, specifically within red blood cells (erythrocytes), where it serves a crucial function in the transport of oxygen throughout the body. This protein has a unique structure that allows it to bind to oxygen molecules in the lungs, where the oxygen concentration is high, and release it in tissues where the oxygen is needed and the concentration is lower.

Hemoglobin's ability to undergo conformational changes in response to the binding and release of oxygen enables efficient gas exchange, and it is also responsible for the characteristic red color of arterial blood. Understanding the role of hemoglobin is fundamental in physiology as it directly relates to how oxygen is distributed and utilized in various bodily functions.

Other alternatives, such as myoglobin, chlorophyll, and albumin, serve different purposes. Myoglobin also binds oxygen but is found in muscle tissues and functions primarily to store oxygen rather than transport it. Chlorophyll is involved in photosynthesis and is not related to oxygen transport in animals. Albumin is a protein in plasma that primarily helps maintain osmotic pressure and transport various substances but is not involved in oxygen transport.