Question

The major function of alpha and beta globulin in the plasma is
A. They develop colloidal osmotic pressure
B. Help in immune response
C. Act as antigens
D. Act as carrier proteins

Answer 1

Hint: Globulins are a type of plasma protein that performs major roles in the body. There are three types of globulins namely alpha globulin, beta globulin and gamma globulin. Their molecular weight is about $$12-900KDa$$. The immune system produces them in the liver. Globulins help in liver function, blood clotting, and fighting infection etc.

Complete answer:
Option A. They develop colloidal osmotic pressure: Colloid osmotic pressure also known as oncotic pressure, is a pressure exerted within the cardiovascular system by proteins found in blood plasma. This pressure balances extracellular water volume. It is induced by a protein called albumin in the blood.
Option A is incorrect.
Option B. Help in immune response: An immune response is a reaction that occurs within an organism for the purpose of defending against foreign invaders such as virus, bacteria, fungi etc. Although alpha and beta globulins help in fighting infection to some extent, it is not their major function.
Option B is incorrect.
Option C. Act as antigens: An antigen is a substance which induces an immune response in the body resulting in production of antibodies. Antigen is generally a foreign substance like virus, bacteria or pollen. Alpha and beta globulins are not antigens
Option C is incorrect.
Option D. Act as carrier proteins: Carrier proteins are proteins that bind to a specific substance and transport them across the cell membrane. One of the major functions of globulins is that they act as carrier proteins. They help transport substances like hormones, cholesterol and iron in the blood. Beta globulins also bind to lipid molecules.
Option D is correct.

Hence, Option D. Act as carrier proteins is the correct answer.

Note:
The normal value of globulins in blood should be $$2-3.5g/dL$$. Abnormal globulin levels can lead to many diseases. It is diagnosed through a globulin test. Low globulin levels indicate liver or kidney disease. High levels can be a sign of infection, inflammatory disease or immune disorders. It can also indicate certain types of cancer like multiple myeloma, Hodgkin's disease or malignant lymphoma.