Summary of Vitamins

Vitamin	Functions	Deficiency	Dietary Level per Day Associated with Overt Deficiency in Adults	Contributing Factors to Deficiency
A Retinol, Retinaldehyde, Retinoic acid, carotene	Visual pigments in the retina; Regulation of gene expression and cell differentiation Beta carotene is an antioxidant), Formation of glycoproteins.	Xerophthalmia, night blindness,  Bitot’s spots, follicular hyperkeratosis, impaired embryonic development, immune dysfunction	<300 μg/d	Fat malabsorption, infection, measles, alcoholism, protein-energy malnutrition
D Calciferol, 1,25 Dihydroxy vitamin D	Maintenance of calcium balance; enhances intestinal absorption of Ca2+ and mobilizes bone mineral; regulation of gene expression cell differentiation and antiproliferative hormone.	Rickets: skeletal deformation, rachitic rosary, bowed legs; osteomalacia In adults	<2.0 μg/d	Ageing, lack of sunlight exposure, fat malabsorption, deeply pigmented skin
E Tocopherols, tocotrienols	Antioxidant, especially in cell membranes; role in cell signaling	Peripheral neuropathy, spinocerebellar ataxia, skeletal muscle atrophy, retinopathy	Not described unless underlying contributing factor is present	Occurs only with fat malabsorption, or genetic abnormalities of vitamin E metabolism/transport
K Phylloquinone: menaquinones	Coenzyme in formation ofgamma carboxyglutamate in enzymes of blood clotting and bone matrix	Elevated prothrombin time, bleeding	<10 μg/d	Fat malabsorption, liver disease, antibiotic use
B1 Thiamine-pyrophosphate	Coenzyme in pyruvate and alpha ketoglutarate dehydrogenases, and Transketolase; Regulates Cl– channel in nerve conduction. Important in carbohydrate and amino acid metabolism	Beriberi: neuropathy, muscle weakness and wasting, cardiomegaly, edema, ophthalmoplegia, confabulation (Wernicke’s encephalopathy withKorsakoff’s psychosis)	<0.3 mg/1000 kcal	Alcoholism, chronic diuretic use, hyper emesis
B2 Riboflavin Flavin mononucleotide (FMN) and Flavin Adenine dinucleotide (FAD)	Coenzyme in oxidation and reduction reactions; prosthetic group of flavoproteins	Magenta tongue, angular stomatitis,  seborrhoea, Cheilosis	<0.6 mg	Riboflavin Deficiency Is Widespread But Not Fatal
B3 Niacin Nicotinic acid, nicotinamide	Coenzyme in oxidation and reduction reactions, functional part of NAD and NADP; role in intracellular calcium regulation and cell signaling	Pellagra: pigmented rash of sun-exposed areas, bright red tongue, diarrhea, apathy, memory loss, disorientation, death in untreated cases	<9.0 niacin equivalents	Alcoholism, vitamin B6 deficiency, riboflavin deficiency, Tryptophan deficiency, Isoniazid therapy, carcinoid syndrome, hart nup disease.
B6 Pyridoxine, Pyridoxal, Pyridoxamine and the phosphorylated derivatives.	Coenzyme in transamination and decarboxylation of amino acids and glycogen phosphorylase; modulation of steroid hormone action	Seborrhea, glossitis, convulsions, neuropathy, depression, confusion, microcytic anemia	<0.2 mg	Alcoholism, isoniazid
Folic acid	Coenzyme in transfer of one-carbon fragments in nucleic acid and amino acid metabolism	Megaloblastic anemia, atrophic glossitis, depression, homocystinuria	<100 μg/d	Alcoholism, Sulfasalazine, Pyrimethamine, Triamterene, Methotrexate
B12 Cobalamine	Coenzyme in transfer of one-carbon fragments and metabolism	Megaloblastic anemia, loss of vibratory and position sense, abnormal gait, dementia, impotence, loss of bladder and bowel control, homocystinemia methylmalonic aciduria	<1.0μ g/d	Gastric atrophy (pernicious anemia), terminal ileal disease, strict vegetarianism, acid reducing drugs (e.g., H2blockers)
Pantothenic acid	Functional part of CoA and acyl carrier protein: fatty acid synthesis and metabolism	Peripheral nerve damage (nutritional melalgia or “burning foot syndrome”)	The vitamin is widely distributed in all food stuffs, and deficiency has not been unequivocally reported in humans	Alcoholism
H Biotin	Co enzyme in carboxylation reactions in gluconeogenesis and fatty acid synthesis; role in regulation of cell cycle	Impaired fat and carbohydrate metabolism, dermatitis		Deficiency is unknown, except total parenteral nutrition, and egg white injury
C Ascorbic Acid	Co enzyme in hydroxylation of proline and lysine in collagen synthesis; antioxidant; enhances absorption of iron	Scurvy: petechiae, ecchymoses, coiled hairs, inflamed and bleeding gums, joint effusion, poor wound healing, fatigue	<10 mg/d	Smoking, alcoholism

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Chemistry Of Proteins-5

1. Why are amino acids called as Amino acids?

(Since they have an amino group and an acid group i.e. Carboxyl group which is ionized at the physiological p H and behaves as a proton donor and is thus an acid)

 2- What is meant by primary amino acids?

(Those amino acids which have a genetic information on the DNA for their synthesis are called as Primary or standard amino acids)

3- What is the linkage between the amino acids in a peptide?

(The amino acids are linked together by a peptide bond which is an anhydrous linkage between the amino acids)

4- Name the amino acids which are derived or modified after translation but are not incorporated in to the tissue proteins.

 (Homocysteine, GABA, Argino succinic acid, Ornithine, Citrulline, etc)

5- Define Denaturation

 ( It is the loss of secondary , tertiary or quaternary structure( if present ) of a protein on exposure to heat, UV light, acids, alkalies, heavy metal salts or even by vigorous shaking, the primary structure is left intact)

6-What is meant by a complete protein, give an example of a complete protein?

( A Complete protein contains all the essential amino acids in an appropriate amount  required for growth, repair and maintenance of body weight.  Example -Egg protein)

7- Give an example of a protein with axial ratios >10:1

(Fibrinogen, keratin, collagen )

8-How many amino acids can be accommodated in one turn of alpha helix?

(3.4 amino acids)

 9- What are chaperones?

 (These are the proteins which participate in the proper folding of the proteins)

10- What is the defect in “transmissible spongiform encephalopathies’?

(These are included under the category of Prion’s diseases and are fatal neurodegenerative diseases characterized by spongiform changes, astrocytic gliomas, and neuronal loss resulting from the deposition of insoluble protein aggregates in neural cells. The protein aggregates are formed of misfolded proteins.)

11-What is the difference between a homodimer and a heterodimer?

(Homodimer contains two copies of the same polypeptide chain, while in a heterodimer the polypeptides differ)

12-What are amphipathic helices?

(The alpha helices having predominantly hydrophobic R groups on one side of the axis of the helix and predominantly hydrophilic ones on the other side are called amphipathic helices)

13-All the amino acids except——- have a chiral centre.

 (Glycine)

14-What is meant by isoelectric  p H ?

 ( It is the p H at which amino acid carries no net electrical charge)

15-Proteins contain only D-amino acids, for which a left handed alpha helix is by far the more stable,  thus only left-handed helices are present in proteins. True or false?

 (False –Proteins contain only L-amino acids, for which a right-handed alpha helix is by far the most stable, and only right-handed alpha helices are present in proteins)

16-Give examples of metalloproteins-

( Alcohol dehydrogenase, glutamate dehydrogenase, Xanthine oxidase  etc. are the examples of metalloproteins

17-Give examples of non standard amino acids which are incorporated in to tissue proteins.

( Hydroxy proline, hydroxy lysine )

18– What is meant by zwitterion ?

( It is the form of amino acid present at its isoelectric p H,  both positive  and negative charges are there but the net charge is zero)

19-Name an indole ring containing amino acid-

(Tryptophan

20- Name the peptides which act as gastro intestinal hormones-

( Secretin, pancreozymin and cholecystokinin)

21- Name the amide group containing amino acids

(Asparagine, Glutamine)

22- What are derived proteins ?

(Proteoses, peptones and peptides etc, the product of digestion and denaturation are called as derived proteins )

23- Give two examples of antibiotic peptides

(Polymyxin, Penicillin, etc )

24-What is the difference between cysteine and cystine ?

( Two cystine residues are joined together by a disulfide bridge to from cystine )

25- What are histones?

( Histones are simple proteins which can bind with DNA to form nucleoproteins, generally they are rich in basic amino acids like Arginine and lysine )

26- Which amino acid disrupts the alpha helical structure of the proteins ?

( Proline and hydroxy proline )

27- Name the components of Glutathione

(Glutamic acid, cysteine and glycine )

28- Name two proteins with a quaternary structure

( Immuno globulins, Hemoglobin, CPK , LDH etc )

29- What are brain peptides ?

( Met encephalin and Leuencephalin)

30- Name a Phospho protein

(Casein, Ovovitellin)

31-What is the product formed after decarboxylation of an amino acid ?

( Amines are formed after decarboxylation of amino acids- like Tryptamine, histamine Tyramine etc)

32-Name the sulphur-containing amino acids-

(Cysteine, cystine and Methionine)

33-Choose the aromatic amino acid out of the following-

Arginine, Histidine, lysine and Tyrosine —— (Tyrosine)

34-Choose an amino acid that does not participate in the alpha helical formation-

Methionine, tryptophan, serine, cysteine——

( Tryptophan )

 35- Millon’s reaction is specific for——- ?      

( Tyrosine )

36- Out of the followings which amino acid is not present in the proteins?

β- Alanine, Histidine, Glycine                  

(β- Alanine)

 37- Name a peptide which acts as a smooth muscle relaxant

( Bradykinin)

38-   What is the nature of prosthetic group in Ceruloplasmin ?

(Copper- It is metalloprotein)

 39- What is a nutritionally poor protein ?Give an example-

( A protein which lacks many essential amino acids is called a poor protein, E.g.- Gelatin

 40- Which protein is abundantly present in hair?    

(Keratin )

41-What is the significance of Biuret test?

 ( It is for the detection of proteins and peptides. Dipeptides and amino acids do not give this test positive, more than two peptide bonds are required for this test to be positive )

42- What is the nature of casein, the milk protein?

( It is a Phospho protein- A conjugated protein)

 43- What is the axial ratio in fibrous proteins?

 ( > 10:1)

 44- In proteins the alpha helical and beta pleated sheet structures are examples of-

Primary, secondary or tertiary structure ?          

( Secondary)

 45- Name an Imidazole ring containing amino acid

(Histidine)

46- Name a peptide  hormone which prevents diuresis –

( ADH)

47 What is the basis of using raw egg for heavy metal poisoning ?

( Egg protein binds with heavy metal to form metal proteinate complex, which is water-soluble and is excretable, else heavy protein binds with tissue proteins to cause damage)

48- The tertiary structure of a protein describes sequence of amino acids- true or false ?

( False- Tertiary structure describes the folding of the protein )

49- Give two examples of haemoproteins.

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

50-  In a protein the disulphide bridges can be broken by–

 ( Reduction )




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Chemistry Of Proteins-4

1- What is the nature of a prosthetic group in a lipoprotein?

 (Lipoprotein is a conjugated protein with lipid as a prosthetic group)

 2- What is the significance of Sakaguchi test?

 (This test is undertaken for the detection of Arginine)

 3- What is the distance traveled per turn in an alpha helix?

 (0-54 nm)

 4- Name an imino acid.

 (Proline, hydroxy proline)

 5-Choose the chromo protein out of the followings-

 Collagen, Keratin, hemoglobin                      

 (Hemoglobin)

 6-Carbonic anhydrase is an example of simple or conjugated protein?

 (It is a conjugated protein, with metal as th prosthetic group)

 7- Name a peptide which acts as an artificial sweetener.

 (Aspartame)

 8- Name the agents which can bring about denaturation of proteins

 (Heat, acids, alkalis, heavy metal salt, UV light, vigorous shaking etc)

 9- Name a tripeptide which acts a reducing agent in the tissues.

 (Glutathione)

 10- Name a peptide which acts as vasoconstrictor

 (Angiotensin-II)

 11- Name the amino acid which is deficient in pulses

 (Methionine)

 12- Choose the odd one out- Collagen, Elastin, Keratin, Histones

 (Histones- The rest three are scleroproteins)

 13- Name two nano peptides

 (Oxytocin, Vasopressin)

 14- Name two globular proteins

 (Hemoglobin, Myoglobin)

 15-Which test should be undertaken for the detection of cysteine in a protein solution?

 (Lead acetate test)

 16-What is the nature of peptide bond- Single, double or partial double bond ?

(Partial double bond)

 17- Out of all the primary amino acids which amino acid gives yellow color on Ninhydrin test?                

 (Proline and hydroxy proline )

 18- Histamine is formed from Histidine by-

 Deamination, decarboxylation or transamination

 (Decarboxylation)

 19- Name two non alpha amino acid

 (GABA, beta Alanine, Delta amino Levulinic acid)

 20- Choose the odd one out-

 Aspartic acid, lysine, Arginine, Cysteine                  

 (Cysteine- Amino acid with uncharged side chain at physiological p H

 21- Choose the odd one out-

Tyrosine, Tryptophan, Threonine                  

 (Tyrosine- non essential Amino acid from the nutritional perspective or threonine if considered non aromatic amino acid)

 22- Name a purely ketogenic amino acid            

 (Leucine)

 23- Name a peptide used as an anticancer drug          

 (Bleomycin)

 24- Name the defense proteins                                    

 (Complement, immunoglobulin)

 25- Choose the odd one out- Silk fibroin, Hemoglobin, Carbonic anhydrase

 (Hemoglobin- The rest are proteins with beta pleated sheet

 26- The proteins with a carbohydrate content > 10 % are called as Mucoproteins- True or false?        

 (True)

 27- The most abundant amino acid in keratin?            

 (Cysteine)

 28- The most abundant amino acid in Collagen—-?    

 (Glycine)

 29- Xanthoproteic test does not specify for—- ?

 Tyrosine, Tryptophan, Serine              

 (Serine)

 30- Give the characteristics of a peptide bond in one line-

 (Rigid, partial double bond, Trans and stable)



31-Name the branched chain amino acids

 (Valine, Leucine, iso Leucine)

 32-Choose the hydrophobic amino acid out of the followings-

 Aspartic acid, Arginine, Serine, Isoleucine

 (Isoleucine)

 33-Which amino acid acts as Methyl group donor?

 (Methionine)

 34- What is the difference between Deamination and Transamination?

(Deamination is the removal of amino group of the amino acid while Transamination is the transfer of amino group from one  donor amino acid to an acceptor keto acid for the formation of a new amino acid)

 35- Out of the 20 amino acids which amino acids participate in the formation of phosphoproteins

 (Serine and Threonine)

 36- Formation of carbamino compound for the transportation of carbon dioxide is a property of amino group, carboxyl group or both groups?

 (Amino group)

 37- Hopkins Cole test is a confirmatory test for which amino acid?

 (Tryptophan)

 38- How many peptide bonds are there in a tripeptide?

 (Two)

 39- The alpha helix is right or left handed?        

 (Right handed)

 40- What is the direction of hydrogen bonds in the beta pleated sheet structure?

 (Perpendicular to the axis)

 41-What is the direction of beta pleated sheets in flavodoxin?

 (Parallel)

 42-Name the most abundant protein in mammals      

 (Collagen)

 43-Name a defect in the primary structure responsible for the causation of a disease

 (Sickle cell disease)

 44-What is the defect in Alzheimer disease?

 (Protein misfolding leading to formation of insoluble protein aggregates)

 45-What is the isoelectric p H of casein?

(4.6)

 46- What is the effect on the solubility of a protein upon denaturation?

 (Solubility decreases upon denaturation)

 47- Name the lipo proteins of biological significance

 (Chylomicrons, VLDL, LDL, HDL)

 48- Which amino acid is lacking in cereals?

 (Cereals lack Lysine)

 49- Which amino acid forms disulphide linkages between two polypeptide chains in oligomeric proteins?                      

 (Cysteine)

 50- Which peptide is used in clinical practice to induce uterine contractions?

 (Oxytocin)


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Chemistry Of Proteins-3

1-Give an example of reversible denaturation

(Denaturation of Ribonuclease by urea)

 2. Give example of a circular peptide.

(Gramicidin S)

 3-What is the difference between Salting in and Salting out?

(Salting in is addition of a pinch of salt to increase the solubility of a protein, while salting out is addition of excess of salt to precipitate it out)

4. Name the proteins containing alpha helical structure predominantly.

(Hemoglobin, Myoglobin etc)

5. Name the super secondary structures

(Greek key, beta meanders, Beta alpha beta)

6. Name the respiratory proteins

(Hemoglobin, Myoglobin, cytochromes)

 7. What is the class of Zein protein?

(Poor protein- it lacks Tryptophan and Lysine)

 8. Name the contractile proteins

( Actin, Myosin, flageller proteins)

 9-What are the features of isoelectric pH?

(Decrease in solubility, electric charge, Electrophoretic migration, loss of biological activity)

 10-What is the basis of protein precipitation by organic solvents?

(Decrease in dielectic constant of the medium)

11-What is the difference between flocculum and coagulum?

(Flocculum is a reversible state of denaturation while coagulum is a an irreversible state of denaturation)

12-What are the forces that stabilize the alpha helical structure?

(Hydrogen and Vander waals forces mainly)

13-What is the basis of cauterization by silver nitrate during surgery to control bleeding?

(Silver nitrate is a heavy metal salt and by causing precipitation of proteins seals the oozing points of the blood vessels)

14-What is meant by a domain?

(Domain is a term used to denote a compact globular functional unit of a protein)

15-Why is Glutathione called a pseudo peptide?

(In glutathione instead of alpha carboxyl group, the gamma carboxyl participates in the peptide bond formation)

16-Covalent forces stabilize the tertiary structure in a protein- True or false?

(False- the non covalent forces stabilize the tertiary structure in a protein)

17- Which tests should be carried out for the detection of Tryptophan in a given solution?

(Xanthoproteic and Hopkins Cole test)

18- Which amino acids contribute towards ionic interactions?

(Positively charged amino acids like Arginine , Lysine and negatively charged amino acids like Aspartic acid and Glutamic acid)

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

(Albumin)

20- What is the relationship of amount of salt required and the molecular weight of a protein?

(More the molecular weight and lesser is the amount of salt required by the protein and vice versa)

21-What are the functions of proteins?

(Nutritive, buffering, defense, viscosity, osmotic pressure, enzymes, hormones etc)

22-Name mono amino dicarboxylic acids

 (Aspartic and Glutamic acid)

 23-Name heterocyclic amino acids

 (Tryptophan and Histidine)

 24-Name the 21st and 22 nd amino acid

 (Seleno cysteine and Pyrrolysine)

 25-Which amino acids are involved in forming N- Glycosidic linkages?

 (Asparagine and Glutamine)

26-Name the semi essential amino acid

(Arginine and Histidine)

27-Which amino acid acts as the precursor of vitamin Niacin?

 (Tryptophan)

28-Name the amino acids with a non polar side chain

(Alanine, Valine, Leucine Isoleucine, Methionine, Phenyl Alanine)

29-Which protein structure determines the relationship of amino acids which are 3-4 residues apart ?

 (Tertiary structure)

30-Which test will be negative for a protein lacking tryptophan ?

 (Hopkins cole test)

 31-Name the essential amino acids

( Valine, Leucine, Isoleucine, lysine, Phenylalanine, Methionine and Threonine)

 32-Which amino acid is optically inactive ?

(Glycine)

 33-Which amino acid is abundantly present in prolamines ?

(Proline)

 34-Which protein is mostly found attached to DNA?

(Histone)

 35-Name the amino acids which are both glucogenic as well as ketogenic

(Isoleucine. Phenyl Alanine, Tyrosine and Tryptophan)

35-Name a specific test for the detection of alpha amino acids

(Ninhydrin test)

 36-Name a  specific test for the detection of cysteine

(Lead acetate test)

37-Covalent bond is formed at which level of protein’s structural organization?

(Primary structure)

38-Name the peptide hormones

 (ACTH, TRH, FSH, Glucagon, PTH, ADH, Oxytocin, Secretin, Pancreozymin, Cholecystokinin)

 39-What is the effect on the biological activity of a protein when exposed to UV light ?

 ( It will lose its biological activity since it will be denatured)

 40-Give two examples of protein misfolding causing disease?

 ( Prion’s and Alzheimer disease)

41-What is the class of casein ?

 (Class 1- complete protein)

42-What are the forces that stabilize quaternary structure of a protein ?

 (Mainly non covalent)

 43-Which amino acid acts as the best buffer of the plasma?

 (Histidine)

 44-What will be the product of decarboxylation of Tyrosine?

 (Tyramine)

 45-Why can’t albumin and majority proteins acquire the native configuration upon denaturation?    

 (Chaperones and other proteins assisting proper folding are not there)

 46-What are Beta bends?

 (Short loops to turn the direction of the beta sheets?

 47-What are the forces that stabilize the beta bends?

 (Hydrogen and electrostatic)

 48-Name a peptide to regulate the volume of urine excreted?

 (ADH)

 49-Which protein is present in the tendons and cartilages?

(Collagen)

 50-Name the storage proteins

 Ferritin, ceruloplasmin)




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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).




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Plasma proteins-questions

1- Name the major proteins of plasma.

(Albumin, Globulin and Fibrinogen)

2-Name the transport proteins

(Albumin, Lipoproteins, Prealbumin, Transthyretin, Retinol Binding protein, Thyroxin binding Globulin)

3-How many copper atoms can bind to one molecule of ceruloplasmin?

(6-8)

4-What is A: G ratio, what is its range in the normal health?                

(1.2:1 to 1.5:1)

5-What is the most significant sign of hypoproteinemia?

 (Edema)

6-Almost all proteins except Globulins are synthesized in the liver, True or false?

(True)

7-Name the negative phase proteins

(Albumin, Transthyretin, Transferrin etc.)

8-What are the different types of light chains?

( Kappa and Lambda)

9-Which immunoglobulin is the major antibody of primary immune response

 (IgM)

10-What is the function of the secretory piece of the IgA?

(It protects the antibody from proteolytic digestion)

11-What is the actual meaning of Fc and Fab ?

(These are the two portions of immunoglobulins produced after proteolytic cleavage of immunoglobulin. Fc denotes fragment crystallisable and Fab denotes antigen binding fragment)

12-Which form of Ig M – monomeric or polymeric acts as a receptor on the surface of B lymphocytes.

( Monomeric form)

13-Which form (Alpha helical, Beta pleated sheet or triple helical) predominates in the structure of collagen?                                  

(Triple helical)

14-What are the different types of heavy chains present in different types if immunoglobulins?

(α, β,γ,δ, Σ)

15-What types of globin chains  are present in Fetal Hemoglobin?

(Two alpha and 2 Gamma)

16-What is methaemoglobin?

( Hb in which iron is in the oxidized form(Ferric form )

17-25 % of the structure of hemoglobin is in the alpha helical form- state true or false?

(False- 75% is in the alpha helical form)

18-Name the beta globulins of biological significance

(Transferrin, Haemopexin, Complement etc)

19-What is the nature of ceruloplasmin?

(Alpha 2 globulin)

20-What is the function of Transferrin?

(Transfer of iron)

21-What is the function of fibrinogen?

(Blood clotting and viscosity)

22-What is the clinical significance of C- reactive protein ?

(Acute phase protein, activates complement, also helps in the formation of haem)

23-What is meant by opsonization?

(Coating the surface of antigen by antibodies)

24-What is the difference between monoclonal and polyclonal antibodies?

(Monoclonal means antibodies of only one specificity while polyclonal means antibodies of different specificities)

25-Hepato lenticular degeneration is observed due to deficiency of which plasma protein?

(Ceruloplasmin)

26-What is the function of complement protein ?

(These are defense molecules present in the plasma in the inactive form, required for pathogenic killing)

27-Enumerate the causes of hypo Albuminemia?

(Hypovolemia, mal nutrition, cirrhosis of liver, losses from the body ),

28-Give two causes of hyperproteinemia

(Hemoconcentration, malignancies, chronic infections)

29-What is class switching?

(The switch from one class of immunoglobulin to another class is called class switching)

30-How are the light chain and heavy chains linked together?

 ( By disulphide linkages)

31-What is the function of carbohydrate in the structure of immunoglobulins?

( It is required for the secretion of antibodies by the plasma calls)

32-Which antibody is called as the mucosal barrier?

( Ig A)

33-Which antibody is called as the Millionaire molecule?

 ( Ig M )

34-How is the rate of catabolism of Ig G affected by its serum concentration?

( It is a direct relationship, more the concentration more is the rate  of catabolism

 35- How many polypeptide chains are present in the structure of myoglobin?

(One)

36-Which out of the two (Myoglobin and hemoglobin) has more affinity for Oxygen?

(Myoglobin)

37-Name two proteins that bind thyroid hormone

(Thyroxin binding protein and Transthyretin)

38-What will be the effect of excessive vomiting on plasma protein concentration ?

( It will result in hyperproteinemia due to hemoconcentration)

39-In a chronic alcoholic patient plasma protein concentration should be lower than normal or higher?

(Lower than normal)

40- What is the function of Transcobalamine?

(Transporter of B12)

41-What are Bence jone’s proteins?

These are light chain Immuno globulins excreted in the urine of a patient suffering from multiple myeloma.

 42- What are the clinical features observed in a patient of multiple myeloma ?

(Weight loss, punched out lesions, anemia , increased frequency of infections)

43-What are the component chains in HbA1?

( 2 alpha and 2 delta)

 44 What is the cause of emphysema in alpha 1 anti trypsin deficiency?

(Inactivated Elastase which causes damage to the lung tissues)


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Plasma proteins

Group	Protein	Function	Clinical Significance
Albumins	a) Albumin b) Transthyretin	a)Maintenance of osmotic pressure;  transport of fatty acids, bilirubin, bile acids, steroid hormones, pharmaceutical drugs, inorganic ions; buffering and nutritive. b)Transport of thyroxin, triiodothyronin and retinol	a)Hypoalbuminemia-Liver cirrhosis, protein energy malnutrition, mal absorption, nephrotic syndrome, protein losing enteropathy, extensive skin burns, genetic disease- Analbuminemia, Hemodilution b) Concentration decreased in all conditions of hypoproteinemia and during infections (Negative acute phase protein)
α1-Globulins	a) Antitrypsin b)  Antichymotrypsin c) Lipoprotein (HDL) d) Prothrombin e) Transcortin f) Acid glycoprotein g) Thyroxin-binding globulin h)Fetoglobulin (Fetoprotein)	a) Inhibition of Trypsin and other proteases b) Inhibition of Chymotrypsin c) Transport of  cholesterol from tissues to liver d) factor II, thrombin precursor e) Transport of cortisol, corticosterone and progesterone f) Transport of progesterone g) Transport of iodothyronins h) Present in fetal blood	a) Acute phase protein (concentration rises  during infections), deficiency associated with Emphysema and liver cirrhosis and acts as a tumour marker- increased level in germ cell tumours of testes and ovaries. - c) Cardio protective (Antiatherogenic) - e) Concentration increases during pregnancy. f)Acute phase protein g) Level – Low in Nephrotic syndrome, High –during pregnancy h) Tumor marker- High concentration in Hepatocellular malignancies
α 2-Globulins	a) Ceruloplasmin b) Antithrombin III c) Haptoglobin d) Cholinesterase e) Plasminogen f) Macroglobulin g) Retinol-binding protein h) Vitamin D-binding protein	a)Transport of copper ions, ferroxidase and Histaminase activities b) Inhibition of blood clotting c) Binding of hemoglobin d) Cleavage of choline esters e) Precursor of plasmin breakdown of blood clots f) Binding of proteases, transport of zinc ions g) Transport of vitamin A h) Transport of Calcitriol	a) Acute phase protein, Low levels in Wilson disease and Menke’s disease. - c) Acute phase protein,Low level in Haemolytic diseases. - - f) Low level in Nephrotic syndrome g) Level of retinol binding protein indicates vitamin A status. h) Low level in Nephrotic syndrome and PEM
β-Globulins	a) Lipoprotein (LDL) b)Transferrin c) Haemopexin d)Sex hormone binding globulin e) Transcobalamine f) C-reactive protein	a) Transport of lipids b) Transport of iron ions c) Binds fee haem d) Transport of testosterone and estradiol e) Transport of vitamin B12 f) Complement activation	a) Atherogenic (Bad cholesterol) b) Negative acute phase protein, low level in all conditions of hypoproteinemia High levels in iron deficiency anemia c)Decreased level in Hemolytic disorders - f)Acute phase protein
Gamma-Globulins	a) IgG b) IgA c) IgM d) IgD e) IgE	a) Main antibody in the secondary response, Opsonizes bacteria, making them easier to phagocytose. Fixes complement, which enhances bacterial killing. Neutralizes bacterial toxins and viruses. Crosses the placenta. b) Mucosa-protecting antibodies Secretory IgA prevents attachment of bacteria and viruses to mucous membranes. Does not fix complement. c) Produced in the primary response to an antigen. Fixes complement. Does not cross the placenta. Antigen receptor on the surface of B cells. d) B-lymphocyte receptors e) Mediate immediate hypersensitivity by causing release of mediators from mast cells and basophils upon exposure to antigen (allergen). Defend against worm infections by causing release of enzymes from eosinophils. Does not fix complement. Main host defense against helminthic infections.	High concentration in  chronic infections, chronic liver diseases, Sarcoidosis, Autoimmune diseases, Multiple myeloma and lymphoreticular malignancies Low concentration in immunodeficiency disorders. c) High concentration  of Ig M -in Waldenstrom’s Macroglobulenemia e) High concentration in allergic disorders and helminthic infections.

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Multiple Choice Questions- Amino acid and protein chemistry

1-A mutation has changed an isoleucine residue of a protein to Glutamic acid, which statement best describes its location in a hydrophilic exterior-

a) On the surface since it is hydrophilic in nature

b) In side the core of the protein since it is hydrophobic in nature

c) Any where inside or outside

d) Inside the core of protein since it has a polar but uncharged side chain

2- Glycine and proline are the most abundant amino acids in the structure of-

a)Hemoglobin

b) Myoglobin

c) Insulin

d) Collagen

3- Some proteins contain additional amino acids that arise by modification of an amino acid already present in a peptide, examples include-

a) 4 -hydroxy proline

b) 5- hydroxy Lysine

c) Gamma Amino Butyric Acid

d) All of the above

4- Choose the incorrect statement out of the followings-

a) Only L amino acids are found in the biological system

b) Glycine is optical inactive

c) Tyrosine is a modified amino acid

d) Seleno cysteine is 21 st amino acid

5- Choose a nano peptide out of the followings-

a) Oxytocin

b) Vasopressin

c) Bradykinin

d) All of the above.

6- Which out of the following amino acids carries a net positive charge at the physiological p H ?

a) Valine

b) Leucine

c) Isoleucine

d) None of the followings.

7- Which out of the following amino acids is a precursor for a mediator of allergies and inflammation?

a) Histidine

b) Tyrosine

c) Phenyl Alanine

d) Tryptophan

8- Mother of a mal nourished child has been instructed to include a complete protein in diet for her child, which out of the followings proteins should be recommended?

a) Pulses

b) Wheat

c) Soy Protein

d) Milk

 9- All of the below mentioned amino acids can participate in hydrogen bonding except one –

a) Serine

b) Cysteine

c) Threonine

d) Valine

10- All of the following amino acids are both glucogenic as well as ketogenic except –

a) Isoleucine

b) Leucine

c) Tyrosine

d) Phenyl alanine

11- Which out of the following amino acid is a precursor of niacin (Vitamin)?

a) Tyrosine

b) Threonine

c) Tryptophan

d) Phenylalanine

12- The greatest buffering capacity at physiological p H would be provided by a protein rich in which of the following amino acids?

a) Serine

b) Cysteine

c) Alanine

d) Histidine

13- Which of the following peptides is cyclic in nature-?

a) Glutathione

b) Gramicidin

c) Met encephalin

d) Leuencephalin

 14- Which out of the followings is not a fibrous protein?

a)Carbonic anhydrase

b) Collagen

c) Fibrinogen

d ) Keratin

15) -Which of the following amino acid is a limiting amino acid in pulses?

a) Leucine

b) Lysine

c) Methionine

d) Glutamine

16)- Which out of the following is not a haemo protein ?



a) Catalase

b) Myeloperoxidase

c) Glutathione peroxidase

d) Aconitase

17- All the below mentioned proteins are metalloproteins except-

a)Carbonic anhydrase

b) Xanthine oxidase

c)  Lactate dehydrogenase

d) Superoxide dismutase                                                                                                      

18- Which out of the following is a peptide antibiotic?

a)Erythromycin

b) Gramicidin

c) Ciprofloxacin

d) Tetracycline

19- Choose the Anticancer peptide out of the followings-

a)Bleomycin

b) Methotrexate

c) Cytosine Arabinoside

d) Dideoxy Inosine

 20- Which of the following amino acids is most compatible with an α- helical structure?

a)Tryptophan

b) Alanine

c) Leucine

d) Proline

21- The highest concentration of cystine can be found in-

a) Melanin

b) Keratin

c) Collagen

d) Myosin

22- In scurvy, which amino acid that is normally part of collagen is not synthesized?

a)Hydroxy Tryptophan

b)Hydroxy Tyrosine

c) Hydroxy Alanine

d) Hydroxy Proline

23- A child with tall stature, loose joints, and detached retinas is found to have a mutation in collagen. Which of the following amino acids is the recurring amino acid most likely to be altered in mutations that distort collagen molecules?

a)Glycine

b) Tyrosine

c) Tryptophan

d) Tyrosine

24- Which one of the following amino acids may be considered a hydrophobic amino acid at physiological p H of 7.4?

a)Isoleucine

b) Arginine

c) Aspartic acid

d) Threonine

25- Which of the characteristics below apply to amino acid Glycine?

a) Optically inactive

b) Hydrophilic, basic and charged

c) Hydrophobic

d) Hydrophilic, acidic and charged

26- Which of the following amino acids in myoglobin, a globular protein, is highly likely to be localized within the interior of the molecule?

a)Arginine

b) Valine

c) Aspartic acid

d) Lysine

 27- Which of the amino acids below is the uncharged derivative of an acidic amino acid?

a)Cystine

b) Tyrosine

c) Glutamine

d) Serine

28-Choose the correct category for milk protein casein out of the followings

a)Nucleoprotein

b) Phospho protein

c) Lipoprotein

d) Glycoprotein





Answers-



1-      a

2-      d

3-      d

4-      c

5-      d

6-      d

7-      a

8-      d

9-      d

10-   b

11-   c

12-   d

13-   b

14-   a

15-   c

16-   d

17-   c

18-   b

19-   a

20-   b

21-   b

22-   d

23-   a

24-   a

25-   a

26-   b

27-   c

28-   b




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Multiple choice questions- Enzymes

Q.1- Glycogen phosphorylase, which mobilizes glycogen for energy, requires which of the followings as a cofactor?
a)Pyridoxal phosphate
b)Tetra hydro folate
c)Adenosyl Cobalamine
d)Coenzyme A                                                          
 (a)
 Q.2-Choose the incorrect statement about Active Site of an enzyme-
a) The active site is a three-dimensional cleft
b) The active site takes up a large part of thetotal volume of an enzyme
c) Substrates are bound to enzymes by multiple weakattractions
d) The specificity of binding depends on theprecisely defined arrangement of atoms in an active site.
(b)
Q.3- Any of the following processes except one are involved at the active site of an enzyme to accelerate the rate of reaction-
a) Catalysis by BondStrain
b) Catalysis byProximity and Orientation
c) Non covalentcatalysis
d) Acid basecatalysis                                                  
 (c)
 Q.4-A given substrate may be acted upon by a number of different enzymes, each of which uses the same substrate(s) and produces the same product(s). The individual members of a set of enzymes sharing suchcharacteristics are known as-
a)Group specific enzymes
b)Isoenzymes
c)Substrate specific enzymes
d)Allosteric enzymes
(b)
Q.5-A recently diagnosed hypertensive patient has been prescribed an ACE inhibitor(Angiotensin convertase inhibitor) which is known to act by lowering V max,what is the possible mechanism of inhibition of this drug?
a)Competitive
b)Non Competitive
c)Uncompetitive
d)None of the above.
(a)
Q.6-Which statement out of the followings is incorrect about the effect of increasing temperature on enzyme activity-
a)Raising the temperature increases the kinetic energy of molecules
b) Aten degree Centigrade rise in temperature will increase the activity of mostenzymes by 50 to 100%.
c)Most animal enzymes rapidly become denatured at temperatures above 40oC
d)Storage of enzymes at 5°C or below is generally not suitable.
(d)
Q.7-A54-year –old male was rushed to emergency when he collapsed in the middle of abusiness meeting. Examination revealed excessive sweating and high bloodpressure.ECG chest was conclusive of Acute Myocardial infarction. Which biochemical investigation out of the followings would  be of no help inthe confirmation of diagnosis?
a) Cardiac Troponins
b)Serum myoglobin
c)Lactate dehydrogenase
d)Creatine Phospho kinase-MB(CPK-MB)
 (c)
Q.8-A coal mine worker was brought in an unconscious state to emergency room aftera blast in the mine. His blood Carboxy hemoglobin level was high and he wasdiagnosed with CO poisoning.  CO is aknown inhibitor of electron transport chain. Which complex of electrontransport chain is inhibited by CO?
a)Complex I
b)Complex II
c)Complex III
d)Complex IV
(d)
Q.9-A 42-year-old obese female presented to theemergency center with complaints of worsening nausea, vomiting, and abdominal pain.Her pain was located in the midepigastric area and right upper quadrant. Blood biochemistry revealed high serum amylase level.What is the probable diagnosis for this patient?
a)Viral hepatitis
b)Acute Pancreatitis
c)Renal colic
d)Acute gastritis
(b)
Q.10-A 60 year old chronic alcoholic was brought to thehospital with complaints of protuberant abdomen (ascites) and edema feet. He also had history of hemorrhages.  Blood biochemistry revealed – High serumtransaminases, low Serum total proteins, Albumin and a prolonged prothrombintime. Urine analysis was normal. What could be the possible diagnosis?
a)Renal failure
b)Protein malnutrition
c)Cirrhosis of liver
d)Heart failure
(c)
Q.11-A 2 -week –old child was brought to theemergency. The parents were fearful that the child had been given some poisonas they noted black discoloration on the diaper. Adiagnosis of Alkaptonuria was made and the child was given Vitamin C as asupplement. Alkaptonuria occurs due to reduced activity of Homogentisic acid oxidaseenzyme. What is the role played by vitamin C in this defect?
a)Acts as an oxidant
b)Acts as a coenzyme
c)Acts as an inducer
d)Acts as a positive allosteric modifier
(b)
Q.12-A67- year-old army officer in good health previously presented with sudden painin the great toe.  Serum uric acid levelwas high, and a diagnosis of gouty arthritis was made He was advised bed rest,pain killers and Allopurinol. What is the mechanism of action of Allopurinol inlowering serum uric acid levels?
a)Suicidal inhibition
b)Non competitive inhibition
c)Allosteric inhibition
d)Feed back inhibition
(a)
Q.13-One out of the following enzymes has absolute specificity for its substrate; choose thecorrect option-
a) Urease
b) Carboxy peptidase
c) Pancreatic lipase
d)Lipoproteinlipase
(a)
Q.14-Which out of the followings is a substrate-specific enzyme?
a) Hexokinase
b)Thiokinase
c) Lactase
d)Decarboxylase
(c)
Q.15-Which out of thefollowings is not a substrate-specific enzyme?
 a)Glucokinase
 b)Fructokinase
 c) Hexokinase
 d)Phosphofructokinase
(c)
Q.16-Group I Co enzymes participate in  which of the followingreactions-
a) Oxidation-reduction
b)Transamination
c) Phosphorylation
d) All of the above
(a)
Q.17-Which out of thefollowing co enzymes takes part in hydrogen transfer reactions in the electron transport chain-
a) Tetrahydrofolate
b) Methyl Cobalamine
c)Co enzyme Q
d) Biotin
(c)
Q.18.The conversion of Pyruvate to oxaloacetate involves the participation of—-  as a coenzyme -
a) NAD+
b) NADPH
c) Biotin
d) All of the above                                                        
(c)
Q.19- The drugFluorouracil is recommended for the treatment of cancers. It undergoes a seriesof changes and then binds to Thymidylate synthase enzyme resulting in itsinhibition and blockage of cell division. This mode of inhibition is mostprobably due to-
a) Allosteric inhibition
b) Competitive inhibition
c) NoncompetitiveInhibition
d) Suicidal inhibition                                                      
(d)
Q.20-The activities ofmany enzymes, membrane transporters and other proteins can be quickly activatedor inactivated by phosphorylation of specific amino acid residues. This regulation is called-
a) Allostericmodification
b) Covalent modification
c) Induction
d) Repression
                                                                                                           
(b)




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Solution to One Word Answer Type Questions- Enzymes

Choose the correct Answer

1) The enzyme that catalyzes the change in location of the functional group from one position to another within a compound is called Isomerase/Mutase.
                                                                                             
(Mutase)
2) The enzyme having low affinity for the substrate will have low/high km.
                                                                                           
(Highkm)
3) The competitive inhibitors increase the Vmax/km but the Vmax/km remains constant.
                                       
(Increase km but the Vmax remains constant)
4) The non- competitive inhibitors decrease the Vmax/km but the Vmax/km remains constant.
                                       
(DecreaseVmax but the km remains constant)
5) The process of induction of an enzyme is a coarse/fine control for regulation of enzyme activity.
                                                                                           
(Coarse control)
6) Arsenate binds to SH group of the enzyme to inhibit its activity and this mode of inhibition is competitive/Non competitive.
                                                                                           
(Noncompetitive)
7) In normal health LDH-1/LDH-2 is in greater concentration in plasma.
                                                                                           
(LDH-2)
8) Transferases are the enzymes which catalyze the transfer of reducing equivalents/groups other than reducing equivalents.
                                                         
(Groups other than reducing equivalents)
9) The enzyme activity increases 2/4 fold with every ten degree rise of temperature
                                                                                           
(2 fold)
10) The reaction rate is zero/first order when the enzyme activity is directly proportional to substrate concentration
                                                                                           
(first-order)
11) The reaction rate is zero/first order when the enzyme activity is independent of substrate concentration
                                                                                           
(Zero order)
12) When the substrate concentration is equal to km the reaction velocity is equal to Vmax/Half Vmax.
                                                                                           
(Half Vmax)
13) Pepsin/Trypsin has an optimum p H of 2.0.
                                                                                           
(Pepsin)
14) Hexokinase/ Glucokinase is inducible
                                                                                           
(Glucokinase)
15) Hexokinase/ Glucokinase is inhibited by feed back inhibition
                                                                                           
(Hexokinase)
16) Alkaline Phosphatase/Acid phosphatase rises in malignancy of prostate gland.
                                                                                           
(Acidphosphatase)
17) LDH/SGOT rises in hemolytic anemias.
                                                                             
(LDH-Lactate dehydrogenase)
18) Methotrexate inhibits dihydrofolate reductase by competitive/Non competitive inhibition.
                                                                                       
(Competitive inhibition)
19) Streptokinase/tPA causes intravascular bleeding as a side effect.
                                                                                         
(Streptokinase)
20) All the Proteolytic/ Lipolytic enzymes are Zymases in nature.
                                                                                     
(Lipolytic enzymes)



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