Topic 4: Functions, fractination and changes of Plasma Proteins

Question 1

What should be mentioned in this topic?

Answer 1

• Synthesis
• Functions
• Fractionation
• Pathological Changes

Question 2

Synthesis:

Answer 2

Almost all the proteins are synthesised in the liver except for gamma globulins, HDL and VLDL and i.c. enzymes

Question 3

Functions:

Answer 3

• Maintaining oncotic pressure (albumin, keeps water in circulation)
• Transport functions of Albumin
• Transport functions of globulins
• Lipids bind to proteins forming lipoproteins
• Blood sedimentation
• Buffer
• Blood clotting
• Immunity
• Enzymes in the plasma (hormone inactivation, diagnostic importance)
• Protein metabolism (change constantly)

Question 4

Functions:

Transport functions of Albumin:

Answer 4

• Fatty acids
• Bilirubin
• Hormones
• Vitamins
• Metal ions

Question 5

Functions:

Transport functions of globulins:

Answer 5

• Transferrin
• Haptoglobin
• Transcortin
• Thyroxin Binding Globulin - Transcobalamin
• Lipoproteins

Question 6

Functions:

Lipids bind to proteins forming lipoproteins:

Answer 6

• VLDL
• LDL
• IDL
• HDL

Question 7

Functions:

Blood sedimentation

Answer 7

• Clinical parameter
• In case of infections acute phase proteins appear in the plasma.
• These are produced by the liver
• Bind to the surface of red bloods cells reducing the charge, causing less repulsion
  between the red blood cells and thus sedimentation becomes faster.

Question 8

Functions:

Buffer action:

Answer 8

Plasma proteins are responsible for 7% buffer capacity of blood, 15% buffer capacity of the plasma

Question 9

Functions:

Blood clotting

Answer 9

• All of the factors involved in blood coagulation except for Ca2+ circulate in the
  intravasal compartment as inactive precursors
• Also responsible for anticoagulation and fibrinolysis

Question 10

Functions:
Immunity:

Answer 10

• Immunoglobulins
• Proteins of non-specific immunity
• Signal proteins and peptides

Question 11

Fractionation:

Answer 11

• Paper electrophoresis
• Gel electrophoresis
• Immunoelectrophoresis
• Ion Exchange chromatography
• HPLC
• Ultracentrifugation
• Gel-filtration
• Affinity Chromatography

Question 12

Fractionation:

Paper electrophoresis

Answer 12

Only Albumin and Fibrinogen can be separated with this method. The rest of the
proteins can be found in the globulin fraction.

Question 13

Fractionation:

Gel electrophoresis

Answer 13

Seperated into albumin, and globulins (a1, a2, b, g)

Question 14

Fractionation:

Immunoelectrophoresis

Answer 14

Antibody distributed in a gel poured on a sheet of glass develops precipitation arcs with the antigen in the electric field

Question 15

Fractionation:

Ion Exchange chromatography

Answer 15

Separates proteins on the basis of their charge

Question 16

Fractionation:

HPLC

Answer 16

High Pressure Liquid Chromatography: divides proteins in a solid phase column
under high pressure perfusion

Question 17

Fractionation:

Ultracentrifugation

Answer 17

Spinning tubes at high G to separate macromolecules according to their sedimentation constants

Question 18

Fractionation:

Gel-filtration

Answer 18

Smaller molecules have to pass through the polysaccharide beads and hence move
slower than bigger beads which just bypass the beads.

Question 19

Fractionation:

Affinity Chromatography

Answer 19

One covalently binds a specific antibody formerly produced against the protein to the granules of the solid phase. The proteins will then be selected from the mixture by a special recognizing system.

Question 20

Pathological Changes

Answer 20

• Hypo and Hyperproteinemia
• Dysproteinemia
• Paraproteinemia
• Defect-proteinemia

Question 21

Pathological Changes:

Hypo and Hyperproteinemia

Answer 21

Brought about by starving, kidney disease

Question 22

Pathological Changes:

Dysproteinemia

Answer 22

Ratio changes

Question 23

Pathological Changes:

Paraproteinemia

Answer 23

Pathological proteins appear

Question 24

Pathological Changes:

Defect-proteinemia

Answer 24

Lack of some of the fractions