Albumin vs Globulin
Human blood is mainly composed of cellular components, which include red and white blood cells, platelets, and blood plasma. Blood plasma is composed of plasma proteins, water, and other solutes. The major compound of blood plasma is water which represents 91.5% of the total plasma volume. Blood proteins constitute only 7% of plasma volume. Albumin, globulin, fibrinogen are the major types of blood proteins found in the plasma. The liver is the responsible organ to produce most of the blood proteins. Out of these three proteins, albumin and globulin represents more than 90% of blood proteins. Thus, the ratio of albumin/globulin (A/G ratio) is used to get a quick view of a patient’s proteins status. Plasma proteins are important in transporting substances such as enzymes, hormones, antibodies, clotting agents etc.
Albumin
Albumin is the major plasma protein in the blood, which constitutes 54% of all blood proteins present in the blood plasma. It is the first human protein, which was produced in plants (tobacco and potato) by genetic engineering. Albumin is produced in the liver using dietary proteins and has half-life of 17-20 days. It is a carrier protein carrying fatty acids, calcium, cortisol, certain dyes, and bilirubin through the plasma, and it also contributes to the oncotic pressure of colloidal proteins.
Deficiency of albumin indicates poor health. The level of albumin may be elevated due to dehydration, congestive heart failure, poor protein utilization etc., whereas it may be decreased due to hypothyroidism, chronic debilitating diseases, malnutrition, skin losses etc.
Globulin
Globulin is a major protein found in blood plasma, which serves as a carrier of steroid and lipid hormones, and fibrinogen; which is needed for blood clotting. There are several types of globulin with various functions and can be divided into four fractions namely; alpha-1 globulin, alpha-2 globulin, beta globulin, and gamma globulin. These four fractions can be obtained separately through the process of protein electrophoresis. Gamma globulin makes the largest portion of all globulin proteins. The globulin level may be increased due to chronic infections, liver diseases, carcinoid syndrome, etc, whereas it may be decreased due to nephrosis, acute hemolytic anemia, liver dysfunction etc.
What is the difference between Albumin and Globulin?
• Blood plasma contains approximately 54% of albumin and 38% of globulin.
• Albumin exerts more oncotic pressure than globulin.
• The molecular diameter of globulin is higher than that of albumin.
• Albumin is one specific protein, whereas there are four fractions of globulin.
• Albumin is a carrier of fatty acids, calcium, cortisol, certain dyes and bilirubin, whereas globulin is a carrier of steroid and lipid hormones, and fibrinogen.