Plasma is a large component of human blood that is comprised of white blood cells, red blood cells and platelets. The liquid substance carries all of these cells throughout the body and transports other important biomolecules when needed.
Plasma makes up approximately 55 percent of the blood in the human body. When isolated from blood, it is yellow in color. The primary purpose of plasma is to transport materials throughout the human body. It transports cells, nutrients, salts, enzymes, hormones and proteins all throughout the body whenever these compounds are needed. Blood plasma also helps transport blood throughout the body.