Question

Serum differs from blood in
(a) Lacking clotting factors
(b) Lacking antibodies
(c) Lacking globulins
(d) Lacking albumins

Answer 1

One of the definitions of serum is ‘blood plasma minus the fibrinogens’. Fibrinogen is an important glycoprotein that is a precursor converted to fibrin on the action of the enzyme thrombin. Fibrin is an important protein that helps the body in case of an injury.

Complete step by step answer:
- Serum differs from blood in lacking clotting factors. The serum is separated from the blood when a blood sample is allowed to clot and further centrifuged to separate the red blood cells and the clot.
- Serum does not contain any proteins required for the clotting of blood. It includes all electrolytes, antibodies, antigens, hormones, any externally supplied substances such as drugs and microorganisms. It also does not contain lymphocytes, erythrocytes, and platelets.
- Serum of convalescent patients, those successfully recovering from an infectious disease, can be used as an agent for the treatment of others suffering from that disease. The generated antibodies present in the serum have a high potential of fighting the same pathogen in other patients. This agent is known as a biopharmaceutical.
- Serum contains antibodies, globulins, and albumins.
- Albumins are a family of water-soluble globular proteins.
- Globulins have higher molecular weights than albumins and belong to the family of globular proteins. They are not soluble in distilled water but are soluble in dilute salt solutions.
So, the correct answer is ‘(a) Lacking clotting factors’.

Note:
- The study of serum is serology. The serum is useful for various diagnostic tests and for the efficacy of drugs in clinical trial studies.
- Fetal bovine serum is extracted from bovine fetuses from slaughterhouses and is an extremely useful growth medium for eukaryotic cell culture.