why blood is red
why blood is red Blood is red because it contains a protein called hemoglobin, which binds with oxygen and gives blood its red color. Hemoglobin is found in red blood cells, which are the most abundant type of blood cell in the body. Hemoglobin contains iron, which is essential for binding with oxygen and carrying it throughout the body. When oxygen binds to hemoglobin, it changes the shape of the molecule and gives blood its bright red color. When oxygen is released from hemoglobin, the molecule returns to its original shape, and the blood appears darker in color. The color of blood can also be affected by other factors, such as the amount of oxygen present, the pH level, and the presence of other compounds. For example, blood that is low in oxygen appears darker in color, such as the blood in veins, while blood that is rich in oxygen appears brighter red, such as the blood in arteries.