Lecture 6-7 (plasma proteins)

Question 1

What is serum

Answer 1

Liquid part of blood after coagulation therefore devoid of clotting factors such as fibrinogen

Question 2

What is plasma

Answer 2

Liquid cells free part of blood, that has been treated with anticoagulants

Question 3

Where are plasma proteins synthesised

Answer 3

In the liver with the exception of immunoglobulins

Question 4

Functions of plasma proteins

Answer 4

Transport 
Maintaining plasma oncotic pressure 
Buffering pH changes 
Defence mechanisms 
Coagulation and Fibrinolysis 
Miscellaneous specialised functions

Question 5

Name the 3 major plasma proteins

Answer 5

Albumin
Globulins
Fibrinogen

Question 6

Where is albumin synthesised

Answer 6

In the liver 12g/day 50% secreted

live in plasma for 2-3 weeks

Question 7

Functions of albumin

Answer 7

Bind and transport diverse molecules

Maintenance of osmotic pressure

Question 8

Name some molecules transported by albumin

Answer 8

Metal ions (calcium and copper)
Free fatty acid
Bilirubin
Bile acid

Question 9

What is colloid osmotic pressure

Answer 9

Form of osmotic pressure exerted by proteins in blood plasma that usually tends to pull water into the circulatory system

Question 10

In relation to osmotic pressure what happens when plasma proteins are reduced

Answer 10

Reduction in osmotic pressure leading to fluid retention (oedema)

Question 11

Name different types of a2-globulins

Answer 11

a2-macroglobulin
haptoglobins
caeuroplasmin
a-fetoprotein

Question 12

What does a2-macroglobulin do

Answer 12

Binds and inactivates endopeptidases such as trypsin

increased nephrotic syndrome

Question 13

Function of haptoglobins

Answer 13

Bind Hb to form HbHp complexes

conserves iron stores in the body

Question 14

When are haptoglobin levels increased or decreased

Answer 14

Increased - acute infection, nephrotic syndrome

Decreased - intravascular haemolysis, liver disease

Question 15

What is caeuroplasmin

Answer 15

a2 - globulins

Copper containing protein binds approx 90%

Question 16

When are caeuroplasmin levels reduced

Answer 16

Wilson’s disease, malnutrition and nephrotic syndrome

Question 17

When are caeuroplasmin levels increased

Answer 17

In pregnancy and in women on oral contraceptives

Question 18

What is alpha-fetoprotein

Answer 18

a2-globulin

Protein present in tissue and plasma of foetus

Question 19

Name beta-globulins

Answer 19

Transferrin

Complement proteins

Question 20

What is atransferrinaemia

Answer 20

Rare congenital deficiency of transferrin

Question 21

When are low levels of transferrin seen

Answer 21

Inflammation and malignancy

Question 22

When are increased levels of transferrin seen

Answer 22

In iron deficiency states

Question 23

How many proteins does the complement system consist of

Answer 23

20

Question 24

What do complement proteins interact with

Answer 24

Sequentially with Ag-Ab complexes
With one another
With cell membranes

Question 25

Where are immunoglobulins synthesised

Answer 25

Lymphoreticular system

Question 26

What is the make up of immunoglobulin molecule

Answer 26

Four polypeptide chains | heavy chain pair and light chain pair

Question 27

Name the 5 heavy chains of immunoglobulins

Answer 27

``` gamma alpha mu delta epsilon ```

Question 28

Name the two types of light chains of immunoglobulins

Answer 28

kappa | lambda

Question 29

Name the 3 major immunoglobulins and 2 minor

Answer 29

IgG IgA IgM Minor: IgD & IgE

Question 30

Function of IgG

Answer 30

Major antibody of the secondary immune response

Question 31

Function of IgA

Answer 31

Secreted as a dimer the major antibodies in the submucous secretions

Question 32

Function of IgM

Answer 32

Pentamer confined to the vascular spaces | the major antibody of the primary response

Question 33

Function of IgD

Answer 33

Present on the surface of B-lymphocytes involved in antigen recognition

Question 34

Function of IgE

Answer 34

Present on surface of mast cells and basophils

Question 35

Where are paraproteins found

Answer 35

In myeloma, in waldenstroms macroglobulinaemia an din heavy chain diseases. These are malignant conditions.

Question 36

What are bence jones proteins

Answer 36

Light chains that spill into urine