Haemoglobin
Hemoglobin
Hemoglobin is the oxygen carrying molecule in red blood cells.
then they are red if they are not carrying oxygen then they are a purple red.
Red blood cells, specifically the protein hemoglobin within red blood cells, is responsible for carrying oxygen in the blood. Hemoglobin binds to oxygen in the lungs and transports it to tissues throughout the body.
White blood cell
Red blood cells
Blood cells that are carrying oxygen will appear bright red, while blood cells that are not carrying oxygen will appear darker in color (usually dark red or purplish). This change in color is due to the presence or absence of oxygen-binding molecules like hemoglobin within the red blood cells.
hemoglobin
Erethrocytes
c02
arteries because they carry blood from the heart,carrying oxygen to the blood cells
The Pulmonary Vein carries oxygenated blood (blood carrying oxygen) to the heart from the lungs and the other superior vena cava and the inferior vena cava (both are veins also) carries de-oxygenated blood (blood not carrying oxygen) to the heart from the body.