medical Definition of organelle : a specialized cellular part (as a mitochondrion or nucleus) that has a specific function and is considered analogous to an organ Learn More about organelle
RBCs take up oxygen in the lungs or gills and release it into tissues while squeezing through the body's capillaries. The cytoplasm of erythrocytes is rich in hemoglobin, an iron-containing biomolecule that can bind oxygen and is responsible for the red color of the cells.ed blood cells are also known as RBCs, red cells, red blood corpuscles (an archaic term), haematids, erythroid cells or erythrocytes (from Greek erythros for red and kytos for hollow vessel, with-cyte translated as cell in modern usage).
Hemoglobin molecules in red blood cells release the carbon dioxide picked up from body tissues and become saturated with oxygen. Carbon dioxide diffuses from the blood to the alveoli, where it is expelled through exhalation.The now oxygen rich blood is returned to the heart and pumped to the rest of the body.his enables oxygen and carbon dioxide to diffuse across the red blood cell's plasma membrane more readily. Red blood cells contain enormous amounts of a protein called hemoglobin. This iron containing molecule binds oxygen as oxygen molecules enter blood vessels in the lungs.