Monday, October 22, 2012

Chemistry of Proteins-2


1- The deficiency of which plasma protein is responsible for Wilson’s disease ?

 (Ceruloplasmin)

2-Which immunoglobulin is pentameric in structure?                  

(Ig M)

3-Which plasma protein is a transporter of free fatty acids?

(Albumin)

4-Which protein acts as reservoir of oxygen?                      

(Myoglobin)

5-What is the normal level of Fibrinogen in the blood?    

(300mg %)

6-Which Immunoglobulin is present at the mucosal surfaces?

( IgA)

7-Complement activation is a function of which part of the Immunoglobulin?

(Fc segment)

8-Which antibody is the first to be synthesized in a fetus ?

(Ig M)

9-What is the function of Hinge region of an immunoglobulin?

(The hinge region confers flexibility and allows both Fab arms to move independently, thus helping them to bind to antigenic sites that may be variable distances apart (eg, on bacterial surfaces).)

10-Name the storage protein of iron                          

(Ferritin)

11-Name a plasma protein that binds extra corpuscular Hb      

(Haptoglobin)

12- γ Globulins are synthesized in the plasma cells- State true or false

(True)

13-What is the nature of apoprotein present in HDLc?                

(α1- globulin)

14-What is specified by CL   in the structure of immunoglobulin?

(Constant region of light chain)

15-What are the consequences of α1- Antitrypsin deficiency?

(Emphysema and cirrhosis of liver)

16-Name a plasma protein which acts as a transporter of Iron

(Transferrin)

17-Maximum contribution to the buffering capacity of plasma proteins is by- ?

(Albumin- due to the presence of histidine residues )

18-Maximum contribution to the viscosity of plasma is by—–?

(Fibrinogen- Since it is an elongated molecule)

19-What is Analbuminemia?

( Congenital absence of Albumin in the plasma)

20- The plasma level of gamma globulins is decreased in chronic liver  diseases True or false ?

(False- The level of gamma globulins is increased in chronic liver diseases)

21-What is the clinical significance related with Alpha feto protein?

  (Its plasma level is increased in liver cell carcinoma and teratoblastomas)

22-What is the function of Alpha 1 acid Glycoprotein?

( Acute phase protein and transporter of Progesterone)

23- What is the significance of the variable region of the immunoglobulins and why is it so-called variable region?

( It is variable in amino acid sequence and is involved in antigen binding)

24- Which plasma protein is a transporter of bilirubin?  

(Albumin)

25- What is meant by acute phase proteins?

(Acute phase proteins are those proteins, the synthesis and thus the plasma level of which are increased in response to inflammation or tissue damage.)

26–What is the difference between plasma and serum?

(Plasma contains clotting factors, while serum lacks them)

27-Out of Albumin, hemoglobin and immunoglobulin, which one has the least molecular weight?                                            

(Hemoglobin)

28-What is the difference between Haemopexin and hemoglobin?

(Haemopexin binds free haem while Haptoglobin binds free hemoglobin.)

29-What is the function of IgD?

(It acts as a receptor on the surface of B lymphocytes)

30-Name the Acute phase proteins

(Alpha 1 Antitrypsin, Alpha 1 acid glycoprotein, Haptoglobin, C-reactive protein)

31-What is the actual meaning of C-reactive protein, what does C mean?

(CRP, so-named because it reacts with the C polysaccharide of pneumococci)

32-Out of lipoproteins, immunoglobulins and Albumin, which one  is a simple protein ?    

(Albumin)

33-Name the plasma proteins involved in the clotting of blood?

(Fibrinogen and clotting factors)

34-Name the defense proteins of plasma

(Immunoglobulins, complement proteins and Beta 2 microglobulin)

35-How is copper transported in the blood?

(It is transported complexed with ceruloplasmin and Albumin)

36-Kayser-Fleischer ring is diagnostic of which disease?

(Wilsondisease)

37-What types of enzyme activities are associated with ceruloplasmin ?

(It has copper dependent Ferro- oxidase activity, it oxidizes iron  from ferrous to ferric form

38-Out of the following proteins which protein has mainly alpha helical structure-

(Collagen, immunoglobulin, myoglobin)              

(Myoglobin)

39-What is the chemical nature of Bence jone’s proteins?

(Light chain of immunoglobulins)                            

40-Name the commonly occurring haemoproteins

(Hemoglobin, Myoglobin, Cytochromes, Peroxidase and Tryptophan Pyrrolase)

41-How does smoking inactivate the Alpha 1 Antitrypsin protein?

(Smoking oxidizes this methionine to methionine sulfoxide and thus inactivates it. As a result, affected molecules of alpha 1-antitrypsin no longer neutralize proteases.)

42-Name three conditions of hyperproteinemia

(Hemoconcentration, chronic infections and malignancies)

43-What is the significance of M band , where is it located ?

(M band is present between beta and gamma globulin regions on electrophoresis of plasma proteins and is diagnostic of Multiple myeloma)

44- How many polypeptides are present in the structure of globin part of hemoglobin ?

(4)

45-Which amino acid contributes maximally to the structure of collagen molecule?

(Glycine)

46- Which immunoglobulin has the cytophilic property?

( Ig E)

47-The number of antibody secreting  plasma cells are decreased in Multiple myeloma that is why there is impaired humoral immune response . True or false?

(False- The number of plasma cells secreting antibodies are increased but these are abnormal and useless antibodies not targeted against any antigen, but the actual humoral response against a specific antigen is decreased.)

48- Which antibody is considered the most potent agglutinating antibody?

(IgM)

49-Which protein is precipitated by full saturation with Ammonium sulphate?

  (Albumin)

50-What is Pre albumin? Why is to so named? Is it a precursor of Albumin?

( Ii is a plasma protein and not a precursor, it is so named because of its faster electrophoretic migration in the electric field).




------------------------------------------ Best Wishes: Dr.Ehab Aboueladab, Tel:01007834123 Email:ehab10f@gmail.com,ehababoueladab@yahoo.com ------------------------------------------

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