Lecture 6-7 (plasma proteins) Flashcards
What is serum
Liquid part of blood after coagulation therefore devoid of clotting factors such as fibrinogen
What is plasma
Liquid cells free part of blood, that has been treated with anticoagulants
Where are plasma proteins synthesised
In the liver with the exception of immunoglobulins
Functions of plasma proteins
Transport Maintaining plasma oncotic pressure Buffering pH changes Defence mechanisms Coagulation and Fibrinolysis Miscellaneous specialised functions
Name the 3 major plasma proteins
Albumin
Globulins
Fibrinogen
Where is albumin synthesised
In the liver 12g/day 50% secreted
live in plasma for 2-3 weeks
Functions of albumin
Bind and transport diverse molecules
Maintenance of osmotic pressure
Name some molecules transported by albumin
Metal ions (calcium and copper)
Free fatty acid
Bilirubin
Bile acid
What is colloid osmotic pressure
Form of osmotic pressure exerted by proteins in blood plasma that usually tends to pull water into the circulatory system
In relation to osmotic pressure what happens when plasma proteins are reduced
Reduction in osmotic pressure leading to fluid retention (oedema)
Name different types of a2-globulins
a2-macroglobulin
haptoglobins
caeuroplasmin
a-fetoprotein
What does a2-macroglobulin do
Binds and inactivates endopeptidases such as trypsin
increased nephrotic syndrome
Function of haptoglobins
Bind Hb to form HbHp complexes
conserves iron stores in the body
When are haptoglobin levels increased or decreased
Increased - acute infection, nephrotic syndrome
Decreased - intravascular haemolysis, liver disease
What is caeuroplasmin
a2 - globulins
Copper containing protein binds approx 90%
When are caeuroplasmin levels reduced
Wilson’s disease, malnutrition and nephrotic syndrome
When are caeuroplasmin levels increased
In pregnancy and in women on oral contraceptives
What is alpha-fetoprotein
a2-globulin
Protein present in tissue and plasma of foetus
Name beta-globulins
Transferrin
Complement proteins
What is atransferrinaemia
Rare congenital deficiency of transferrin
When are low levels of transferrin seen
Inflammation and malignancy
When are increased levels of transferrin seen
In iron deficiency states
How many proteins does the complement system consist of
20
What do complement proteins interact with
Sequentially with Ag-Ab complexes
With one another
With cell membranes
Where are immunoglobulins synthesised
Lymphoreticular system
What is the make up of immunoglobulin molecule
Four polypeptide chains
heavy chain pair and light chain pair
Name the 5 heavy chains of immunoglobulins
gamma alpha mu delta epsilon
Name the two types of light chains of immunoglobulins
kappa
lambda
Name the 3 major immunoglobulins and 2 minor
IgG
IgA
IgM
Minor: IgD & IgE
Function of IgG
Major antibody of the secondary immune response
Function of IgA
Secreted as a dimer the major antibodies in the submucous secretions
Function of IgM
Pentamer confined to the vascular spaces
the major antibody of the primary response
Function of IgD
Present on the surface of B-lymphocytes involved in antigen recognition
Function of IgE
Present on surface of mast cells and basophils
Where are paraproteins found
In myeloma, in waldenstroms macroglobulinaemia an din heavy chain diseases. These are malignant conditions.
What are bence jones proteins
Light chains that spill into urine
