Preparatory Guide on Biochemistry, Molecular Biology, Physiology, Microbiology, Immunology, Pharmacology & Drug Discovery

Renal Function, Acid-Base Balance & Acid Base Disorders: MCQ

April 29, 2018
The renal system covers the glomerular functiontubular functionacid-base homeostasis,  biochemical assessment,  and clinical correlations. The glomerulus is mainly involved in the filtration of the blood for the excretion of waste products while retaining most of the proteins. The renal tubules function in secretion, reabsorption, and excretion of electrolytes, ions, organic acids, urea. The renal tubules help regulate osmolality, volume, and pH of the blood. 

Physiological function of Kidney & Acid-Base Balance 
Multiple Choice Question

1) The normal arterial blood pH is approximately 7.4. Select the hydrogen ion concentration that corresponds to the pH 7.4. (Hint: Use pH = log 1/[H+] )
a) 35 mEq/L
b) 40 mEq/L
c) 45 mEq/L
d) 50 mEq/L

2) The following are the primary system that regulates the acid-base homeostasis. Which of the following is the most powerful regulatory mechanism?
a) Chemical buffer system
b) Protein buffer system
c) Respiratory mechanism
d) Renal mechanism

3) The following are the primary system that regulates the acid-base homeostasis. Which of the following is the first acting regulatory mechanism?
a) Chemical buffer system
b) Protein buffer system
c) Respiratory mechanism
d) Renal mechanism

4) The bicarbonate buffer systems play a vital role in acid-base homeostasis. The body can easily interconvert the carbonic acid into bicarbonate ion or carbon dioxide to regulate maintain the change in hydrogen ion concentration. Identify the equation that represents the relation of carbon dioxide and bicarbonate ions in the maintenance of blood pH
a) pH = 6.1 + log { HCO3-/[0.03 XPco2]}
b) pH = 6.8 + log { HCO3-/[0.03 XPco2]}
c) pH = 6.1 + log { HCO3-/[0.05 XPco2]}
d) None of the above

5) Identify the correct ratio of bicarbonate to carbon dioxide in the extracellular fluids under normal physiological condition.
a) 16: 1
b) 20: 1
c) 24: 1
d) 28: 1

6) The respiratory system regulates the acid-base balance by controlling the carbon dioxide concentration in the extracellular fluid. Which of the following statement are false the respiratory regulations?
a) Increase in ventilation eliminates CO2 from the extracellular fluid and reduces H+ concentration
b) Increase in ventilation eliminates CO2 from the extracellular fluid and increases H+ concentration
c) A decrease in ventilation increases CO2, thereby increasing hydrogen ion concentration in extracellular fluid
d) All of the above

7) Which of the following statement is true regarding the respiratory control of acid-base maintenance?
a) Increase in hydrogen ion concentration stimulates the respiratory system
b) The respiratory system can effectively correct the hydrogen ion concentration by 50% to 70%
c) The impairment of lung function in a condition such as emphysema increases the pCO2 concentrations
d) All of the above

8) What is the site of reclamation of bicarbonate?
a) Glomerulus
b) Proximal Tubules
c) Loop of Henle
d) Distal Tubules

9) Which of the following processes are true regarding reclamation of bicarbonate by the kidney tubules except?
a) The hydrogen ions are secreted into the renal tubules via Na+ H+ ATPase transporter
b)  The secreted hydrogen ion combines with bicarbonate to form carbonic acid.
c) The carbonic acid is converted into water and carbon dioxide and the CO2 diffuses into the cells
d) The process involves net reabsorption of one bicarbonate and secretion of one hydrogen ion

10) The second renal mechanism for the maintenance of acid-base homeostasis is the active secretion of a hydrogen ion from the distal tubules and collecting ducts. The following statements are true regarding hydrogen ion secretion:
a)  The carbon dioxide in the intercalated cells are converted into hydrogen and bicarbonate involving carbonic anhydrase
b) The hydrogen ions secreted by the Na+/H+ pump in the intercalated cells  are sequestered as titrable acid (H2PO4) or ammonium ions for excretion
c) The bicarbonate from the intercalated cells returns into the circulation
d) All of the above

11) The Kidney contributes to acid-base balance by:
a) Secretion of ammonia
b) Reclamation of bicarbonate
c) Increased ketogenesis
d) Decreased CO2 uptake

12) Excess Carbon dioxide (CO2) found in the following non-compensated conditions
a) Metabolic acidosis
b) Metabolic alkalosis
c) Respiratory acidosis
d) Respiratory alkalosis


13) Which of the following buffer system is present at high concentration inside the cells and serve as an effective intracellular buffer in our body?
a) Bicarbonate buffer system
b) Albumin buffer system
c) Ammonia buffer system
d) Phosphate buffer system

14) Which of the following condition has a normal anion gap?
a) Ketoacidosis
b) Lactic acidosis
c) Hyperchloremic metabolic acidosis
d) Uremia

15) Which of the following remain unchanged during metabolic acidosis without respiratory compensation?
a) Bicarbonate Ion
b) Hydrogen ion
c) Anion Gap
d) The partial pressure of carbon dioxide

16) In Renal tubular acidosis type I, which of the following statement is true?
a) Bicarbonate re-absorption is impaired
b) Hydrogen ion secretion is impaired
c) Urinary pH is acidic below 5.5
d) Aldosterone action is impaired.

17) Which of the following best describes the condition ketoacidosis?
a) metabolic acidosis with a high anion gap
b) metabolic acidosis with a normal anion gap
c) respiratory acidosis with a high anion gap
d) respiratory acidosis with a normal anion gap



18) A 10-year-old body develops severe diarrhea while traveling to India. The laboratory investigation revealed the following:
Arterial blood pH = 7.25
Partial Pressure of carbon dioxide = 24 mmHg
Bicarbonate = 10 mEq/L
Normal anion gap
The correct diagnosis of this patient is

a) metabolic acidosis
b) metabolic alkalosis
c) respiratory acidosis
d) respiratory alkalosis

19) Which of the following condition causes metabolic alkalosis?
a) Uncontrolled diabetes mellitus
b) Starvation
c) Excess alcohol
d) Excess Aldosterone

20) The difference between unmeasured anions and unmeasured cations is estimated as the anion gap. Select the correct anion gap when
Sodium = 144 mEq/L
Potassium = 24 mEg/L
Chloride = 108 mEq/L

a) 10
b) 20
c) 30
c) 40

Multiple Choice Answers
1-b) 40 mEq/L
2-d) Renal mechanism
3-a) Chemical buffer system
4-a) pH = 6.1 + log { HCO3-/[0.03 XPco2]}
5-b) 20: 1
6-b) Increase in ventilation eliminates CO2 from the extracellular fluid and increases H+ concentration
7-d) All of the above
8-b) Proximal Tubules
9-d) The process involves net reabsorption of one bicarbonate and secretion of one hydrogen ion
10-d) All of the above
11-b) Reclamation of bicarbonate
12-c) Respiratory acidosis
13-d) Phosphate buffer system
14-c) Hyperchloremic metabolic acidosis
15-d) The partial pressure of carbon dioxide
16-b) Hydrogen ion secretion is impaired
17-a) metabolic acidosis with a high anion gap
18-a) metabolic acidosis: decreased Pco2 is a result of respiratory compensation
19-d) Excess Aldosterone
20-a) 10


Renal Function, Acid-Base Balance & Acid Base Disorders: MCQ Renal Function, Acid-Base Balance & Acid Base Disorders: MCQ Reviewed by Biotechnology on April 29, 2018 Rating: 5

Liver Function and Metabolism: MCQ

April 29, 2018
Multiple Choice Question 
Liver Function and Metabolism

1) Fatty liver is caused by the accumulation/deposition of fats in the liver. Which of the following is not the likely cause of fatty liver?
a) Obesity
b) Starvation
c) Pregnancy
d) Diabetes mellitus

2) Which of the following is the nonfunctional plasma enzymes increased in alcoholic subjects?
a) Alkaline phosphatase
b) Acid Phosphatase
c) Lactate dehydrogenase
d) Gamma-glutamyl transferase

3) Criggler Najjar syndrome is a genetic disorder associated with unconjugated hyperbilirubinemia. What is the deficient enzyme responsible for the disease?
a) Heme oxygenase
b) Biliverdin reductase
c) Bilirubin UDP-glucuronosyl synthase
d) Bilirubin UDP-glucorunly transferase

4) All of the following statement is true concerning urobilinogen except:
a) Produced by oxidative action of intestinal bacteria.
b) Undergoes significant enterohepatic circulation.
c) Urinary levels increased in biliary obstruction.
d) Fecal levels decreased in biliary obstruction.

5) Galactosemia is caused by a deficiency of the enzyme responsible for the galactose metabolism. Which of the following enzyme is deficient?
a) Galactokinase
b) Galactose 1- phosphate uridyl transferase
c) UDP-4- Epimerase
d) Galactose dehydrogenase

6) The biochemical investigation of the blood specimen showed Bilirubin- 4.5 mg/dl, ALT- 150 IU/L, AST- 200 IU/L, Albumin- 25 mg/dL. What is the likely biochemical diagnosis?
a) Hemolytic Jaundice
b) Acute hepatic disease
c) Chronic hepatic disease
d) Obstructive liver disease

7) Which of the following enzyme is a sensitive marker of alcoholic liver disease?
a) Alanine transaminase
b) Aspartate transaminase
c) Alkaline phosphatase
d) Gamma-Glutamyltransferase

8) Which of the following marker is used for the differential diagnosis of obstructive jaundice?
a) Lactate dehydrogenase
b) Creatine Kinase
c) Carbonic anhydrase
d) 5’- Nucleotidase

9) Criggler’s Najjar Syndrome II occurs due to
a) Excessive production of bilirubin
b) The absence of conjugating enzyme
c) Partial deficiency of a conjugating enzyme
d) Overexpression of conjugating enzymes

10) Gluconeogenesis occurs in the liver because of the presence of
a) Phosphofructokinase
b) Pyruvate carboxylase
c) Glucose 6 phosphatase
d) Glucokinase

Multiple Choice Question Set I Answers
1-b, 2-d, 3-d, 4-b, 5-b, 6-c, 7-d, 8- d, 9-c, 10- c

Multiple Choice Question Set II
11) Which the following statements is true of warfarin?
a) competitive antagonist of vitamin
b) co-administration of aspirin is safe
c) prolonged prothrombin time
d) reduced synthesis of coagulation factor VIII.

12) Starch contains glucose units with 1-4 and 1-6 bonds and which enzyme helps to hydrolyze branched chain?
a) amylase
b) maltase
c) isomaltase
d) sucrase

13)Which of the following molecule is the substrate for ketogenesis?
a) alanine
b) oxaloacetate
c) triacylglycerol
d) acetyl CoA

14) Which of the following enzyme is a sensitive marker of alcoholic liver disease?
a) Alanine transaminase
b) Aspartate transaminase
c) Alkaline phosphatase
d) Gamma-Glutamyltransferase

15) Which of the following marker is used for the differential diagnosis of obstructive jaundice?
a) Lactate dehydrogenase
b) Creatine Kinase
c) Carbonic anhydrase
d) 5’- Nucleotidase

16) Criggler’s Najjar Syndrome II occurs due to
a) Excessive production of bilirubin
b) Complete Absence of conjugating enzyme
c) Partial deficiency of the conjugating enzyme
d) Overexpression of conjugating enzymes

17) Which of the following enzyme regulates TCA cycle:
a) malate dehydrogenase
b) fumarase
c) isocitrate dehydrogenase
d) succinate dehydrogenase

18) A person is suffering from glycogen storage disease known as von Gierke disease. Identify the missing enzyme from the following
a) glucokinase
b) glucose-6- phosphatase
c) phosphoglucomutase
d) phosphoglucoisomerase

19) What deficiency causes Korsakoff –Wernicke disease
a) high-calorie intake from carbohydrate
b) high intake of energy from alcohol
c) high intake of fat for energy
d) high intake of protein for energy

20) Which of the following trace metal are localized in the taste bud and play an important role structural component of taste bud?
a) Cu (copper )
b) Zn (zinc)
c) Cr (chromium)
d) Fe (iron)

21) Identify the pentose phosphate pathway intermediate that oxidizes and generates co-enzyme NADPH
a) fructose 6 phosphate
b) ribose-5-phosphate
c) glucose -6 phosphate
d) glucose -1 phosphate

Multiple Choice Question Set II Answers
11- a, 12-c, 13-d, 14-b, 15-d, 16-c, 17-d, 18-b, 19-c, 20-b, 21-c



Liver Function and Metabolism: MCQ Liver Function and Metabolism: MCQ Reviewed by Biotechnology on April 29, 2018 Rating: 5

Molecular Biology: MCQ on DNA synthesis (Replication)

April 29, 2018





Multiple Choice Question Set I on 

Molecular Biology: DNA synthesis (Replication)


1) In most organisms, DNA is a genetic material which stores the information template for the synthesis of RNA and subsequently protein. Name the processes a, b, c represented in the figure:



Central Dogma of Molecular Biology

2) In some viruses, RNA serves as the storage of genetic materials and DNA is synthesized from RNA by the enzyme known as:
a) DNA synthetase
b) DNA polymerase
c) Reverse transcriptase
d) DNA convertase

3) Which of the following process does not occur in prokaryotes
a) Replication
b) Transcription
c) Translation
d) Splicing

4) Phosphodiester bond links two nucleotides together and maintains polarity which refers to:
a) the 5' hydroxyl group of pentose of one nucleotide to 3' hydroxyl group of adjacent nucleotide through a phosphate group.
b) 5' end with a phosphate group and 3'end with hydroxyl are free.
c) addition of new nucleotide occurs via attachment of 5' phosphate group of new nucleotide to 3' phosphate group of an existing chain.
d) All of the above
5) DNA helices exist in various form. Which of the following form is predominantly expressed in cells
a) A-Helix
b) B- Helix
c) E-Helix
d) Z-Helix

6) Which one of the following statement is true regarding the DNA double helical structure?
a) The DNA double helix is coiled around a common axis know as the axis of symmetry
b) The hydrophilic deoxyribose-phosphate backbone of each chain is on the outside.
c) The hydrophobic nitrogen bases are stacked inside.
d) All of the Above

7) The spatial arrangement DNA helical structure creates a major and minor groove which are important for
a) kinking and bending of the helical structure
b) providing recognition and binding sites for various DNA binding proteins
c) All of Above
d) None of Above

8) Aminoglycoside antibiotics such as kanamycin, tobramycin, neomycin are known inhibitors of DNA synthesis. It contains a cyclitol ring linked to a five or six membered sugars by glycosidic bonds. These antibiotics are
a) Positively charged compound that to DNA and intercalates it.
b) Positively charged compound that binds to DNA polymerase activity.
c) Negatively charged compound to DNA and denatures it.
d) Negatively charged compound that binds to histones

9) The Chargaff rules state that the number of purines and pyrimidines are equal (A+G = T + C)in any double-stranded DNA molecules. Watson and Crick later solved the structure of DNA and nitrogen base pairings. Which of the following base pairing rule is true:
a) Adenine pairs with Guanine and Thymine pairs with Cytosine
b) Adenine pairs with Thymine and Guanine pairs with Cytosine
c) Adenine pairs with Cytosine and Guanine pairs with Thymine
d) DNA base pairing is nonspecific

10) The DNA replication occurs in a semi-conservative manner which means
a) Two daughter cells with one consisting of double helical parent DNA, others have newly synthesized DNA.
b) Two daughter cells each consisting one parental strand and one newly synthesized DNA.
c) Two daughters cells each consisting of one-half parental and another half newly synthesized DNA resulting from the crossover.
d) None of the above
11) Which of the followings are the characteristic feature of DNA replication
a) DNA replication is template directed
b) DNA replication requires short RNA primers
c) DNA replication is a highly accurate process
d) All of the Above

12) In prokaryotes, DNA replication begins at a single site that is rich in AT nucleotide sequence, where two strands unwind and separate. This ATP dependent process catalyzed by a protein
a) DnaA protein
b) Single strand binding protein
c) DNA polymerase
d) Topoisomerase

13) The short strand of ........ primer is required for the replication of DNA:
a) DNA
b) RNA
c) Histone
d) hnRNA

14) As the two strands of the double helix are separated, the positive supercoiling interferes with the further unwinding of DNA. Which of the following enzyme makes a break in a strand of DNA to release the supercoiling and facilitate the replication to occur?
a) DnaA protein
b) Single-strand binding protein
c) DNA polymerase
d) Topoisomerase

15) Which of the following enzyme has a unique ability to introduce positive and negative supercoiling of the DNA and it is the target for antibacterial agents such as ciprofloxacin/quinolones?
a) DnaA protein
b) DNA helicase
c) DNA gyrase
d) DNA polymerase

16) DNA replication is bidirectional and anti-parallel. Which of the statement is FALSE regarding the DNA replication?
a) The DNA synthesis i.e. addition of nucleotide occurs from 5'-3' position
b) The DNA synthesis is semi-continuous with continuous leading strand and discontinuous lagging strand.
c) The synthesis of leading and lagging strands occurs simultaneously
d) None of the Above

17) The DNA polymerase is a template-directed enzyme that synthesizes new complementary strand from a parent strand but it requires the existing short nucleotide sequence for its elongation. Which of the following enzyme is required for the synthesis of this primer?
a) Primase/RNA polymerase
b) RNA synthase
c) DNA synthase
d) Helicase
18) DNA polymerase III holoenzyme possesses:
a) polymerase activity only
b) 3’→ 5’ endonuclease activity
c) 3’→ 5’ exonuclease activity and polymerase activities
d) 5’→ 3’ exonuclease activity

19) Which of the following statement is true regarding an enzyme DNA polymerase that catalyzes the elongation of complementary DNA strand?
a) DNA polymerase III is a highly processive enzyme.
b) DNA polymerase III possess 5'-3' polymerase activity required for elongation.
c) DNA polymerase III possess 3'-5' exonuclease activity important for maintaining fidelity.
d) All of the above

20) In prokaryotes, the RNA primer from the lagging strand is removed and replaced by the DNA sequence. This process is catalyzed by an enzyme ............... which possess 5'-3' exonuclease activity and 5'-3' polymerase activity.
a) DNA polymerase I
b) DNA polymerase II
c) DNA polymerase III
d) DNA polymerase IV

21) In eukaryotes, DNA polymerase alpha is a multi-subunit enzyme with different functions. They include:
a) Elongation of the leading strand
b) 3'-5' exonuclease activity
c) Initiation and synthesis of RNA primer
d) High processivity

22) In eukaryotes, which of the following DNA polymerase is highly processive and required for the elongation phase of DNA replication?
a) Pol alpha
b) Pol beta
c) Pol gamma
d) Pol delta

23) In eukaryotes, which of the following DNA polymerase is required for mitochondrial DNA replication?
a) Pol alpha
b) Pol beta
c) Pol gamma
d) Pol delta

24) Telomeres are the repetitive sequence of T's and G's that are present in the eukaryotes to protect the random cleavage from nucleases. These telomeres are synthesized by the enzyme telomerase. Which of the following are the properties of enzyme telomerase?
a) Telomerase is a reverse transcriptase enzyme
b) Telomerase consist of an RNA sequence that serves as a template
c) After completion of each cycle, telomerase translocates to 3'end of DNA to synthesize repetitive sequence.
d) All of the above

Multiple Choice Answers

1- a)- Replication, b-Transcription, c- Translation

2- c) Reverse transcriptase

3- d) Splicing
4- d) All of the above 
5- b) B- Helix 
6- d) All of the Above
7- b) providing recognition and binding sites for various DNA binding proteins 
8- a) Positively charged compound that to DNA and intercalates it.
9- b) Adenine pairs with Thymine and Guanine pairs with Cytosine
10- b) Two daughter cells each consisting one parental strand and one newly synthesized DNA
11- d) All of the Above 
12)- a) DnaA protein  
13- b) RNA
14 d) Topoisomerase
15- c) DNA gyrase
16- d) None of the Above 
17- a) Primase/RNA polymerase
18- c) 3’→ 5’ exonuclease activity and polymerase activities 
19- d) All of the above 
20-a) DNA polymerase I
21- c) Initiation and synthesis of RNA primer 
22- d) Pol delta 
23- c) Pol gamma
24- d) All of the above
Molecular Biology: MCQ on DNA synthesis (Replication) Molecular Biology: MCQ on DNA synthesis (Replication) Reviewed by Biotechnology on April 29, 2018 Rating: 5
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