Types of Plasma Proteins: Albumin, Globulin, Fibrinogen
Start with the big picture
Albumin is the most abundant plasma protein and contributes substantially to colloid osmotic pressure. It is made by hepatocytes, carries diverse substances, and also supports antioxidant activity and buffering. Reduced albumin can contribute to edema and ascites, with several possible underlying causes. Globulins comprise α₁, α₂, β, and γ groups, whose varied roles include transport, protease inhibition, complement activity, and antibody-mediated immunity. The albumin/globulin ratio and acute-phase response provide useful context for interpreting shifts in protein patterns. Fibrinogen, a liver-derived coagulation protein, is converted to fibrin by thrombin; reduced levels can be associated with bleeding. The lesson also introduces the order in which major fractions migrate during serum protein electrophoresis.
What you'll learn
- Describe the major functions of plasma proteins collectively.
- Explain albumin synthesis, key functions, and clinical implications of reduced levels.
- Distinguish the major globulin subclasses by representative proteins and roles.
- Relate the A/G ratio and acute-phase response to plasma protein changes.
- Summarize fibrinogen’s role in coagulation and its clinical relevance.
Continue your study
Work through the complete notes and reinforce the topic with the study tools available in the full lesson.
