Each component of blood has its own individual and beneficial characteristics. Plasma is primarily water, but also contains sugar, fat, protein, salts, and chemicals that aid in blood clotting. Red blood cells contain hemoglobin, which transports oxygen and carbon dioxide throughout the body as needed and is responsible for the color of the cells. White blood cells are larger than the red counterparts and produce antibodies that help fight bodily infection and disease. Platelets, however, are fragments rather than complete cells. If the body suffers an injury, platelets gather and stick to the edges of the wound, as well as release chemicals that help start the clotting process.