M2 DRILLS Flashcards
Which of the following is an advantage eukaryotes have over prokaryotes?
A. Increased stability of genetic information due to double-stranded DNA
B. Increased compartmentalization allowing for specialization
C. Streamlined transcription / translation process due to clear step-wise mechanism
D. Improved cell motility due to protein-based flagella
B.
Increased compartmentalization allowing for specialization
Plays a variety of roles, but an especially notable role is the processing of exogenous chemicals (chemicals originating outside the cell) such as drugs.
A. Golgi Complex
B. Smooth ER
C. Lysosome
D. Secretory granules
E. Rough ER
B.
Smooth ER
Select the correct statements about membrane channels:
I. Membrane permeability is conferred by 3 classes of membrane proteins: pumps, carriers and channels
II. Pump action is an example of passive transport
III. Channels provide a membrane pore through which ions can flow very rapidly in a thermodynamically downhill direction
IV. The transport of molecules across a membrane is always by active transport
A. I, II, III, IV
B. II, III, IV
C. I, III
D. II, IV
C.
I, III
Which of the following statements is/are correct?
I. Amino acids, consisting of a central carbon linked to an amino group, a carboxyl group, a distinctive side chain and a hydrogen atom, are chiral with the exception of Proline.
II. Only the L isomer exist in natural proteins.
III. Lysine, arginine and histidine are positively charged at neutral pH.
IV. A human adult can synthesize enough arginine to meet his or her needs.
A. I, II, III
B. II and III
C. III only
D. II, III, and IV
E. All of the above
D.
II, III, and IV
The amino acid Histidine has 3 ionizable groups with pKa values of 1.82, 6.00 and 9.17. Calculate the pI of Histidine.
A. 3.91
B. 5.50
C. 5.66
D. 7.59
D.
7.59
Separating proteins on the basis of size.
A. Gel-filtration chromatography
B. Ion-exchange chromatography
C. Affinity chromatography
D. High pressure chromatography
E. Isoelectric focusing
A.
Gel-filtration chromatography
Which of the following properties of a protein is least likely to be affected by changes in pH?
A. Tertiary structure
B. Net charge
C. Secondary structure
D. Primary structure
D.
Primary structure
Refers to the spatial arrangement of amino acid residues that are far apart in the sequence.
A. Secondary structure
B. Supersecondary structure
C. Tertiary structure
D. Quaternary structure
C.
Tertiary structure
In this condition, which can vary from mild to very severe, other amino acids replace the internal glycine residue resulting in a defective collagen.
A. Scurvy
B. Osteogenesis imperfecta
C. Osteoporosis
D. Ehlers-Danlos syndrome
B.
Osteogenesis imperfecta
Which of the following pairs is correct?
A. Hemoglobin: storage protein
B. Fibrinogen: defensive protein
C. Fibroin: enzymatic protein
D. Ferritin: transport protein
B.
Fibrinogen: defensive protein
Which of the following amino acids is essential and both glucogenic and ketogenic?
A. Isoleucine
B. Leucine
C. Lysine
D. Histidine
A.
Isoleucine
In the binding of oxygen to myoglobin, the relationship between the concentration of oxygen and the fraction of binding sites occupied can best be described as:
A. Hyperbolic
B. Linear with positive slope
C. Parabolic
D. Sigmoidal
A.
Hyperbolic
Which of the following is a function of chaperone protein?
A. It degrades proteins that have folded improperly
B. It provide a template for how the proteins should fold
C. It rescues proteins that have folded improperly and allows them to refold properly
D. It degrades proteins that have folded properly
C.
It rescues proteins that have folded improperly and allows them to refold properly
Indole ring is detected using this qualitative test.
A. Sakaguchi test
B. Hopkins-Cole
C. Millonase test
D. Pauly’s Diazo test
B.
Hopkins-Cole
Neurodegenerative diseases such as Mad Cow and Kuru diseases are caused by infectious particles called
A. Coronavirus
B. Viroids
C. Retrovirus
D. Prions
D.
Prions
Enzymes catalyze biochemical reactions by altering which of the following quantities associated with the reaction?
A. The enthalpy of formation, DH
B. The activation energy, Ea
C. The change in Gibb’s free energy, DG
D. The equilibrium constant, Keq
B.
The activation energy, Ea
Phosphoglucomutase, which catalyzes the formation of glucose-6-phosphate from glucose-1-phosphate, is best classified as which of the following enzyme type?
A. Class I
B. Class II
C. Class III
D. Class IV
E. Class V
E.
Class V
Molecule ‘X’ is an enzyme inhibitor that reversibly binds to an enzyme at a site that is distinct from its active site. Molecule ‘X’ must NOT be what type of inhibitor?
A. Mixed inhibitor
B.Competitive inhibitor
C.Noncompetitive inhibitor
D.Uncompetitive inhibitor
B.
Competitive inhibitor
The catalytic efficiency of two distinct enzymes can be compared based on which of the following factor.
A. Km
B. Product formation
C. Size of the enzymes
D. pH of optimum value
A.
Km
Asparaginase is sometimes used as a chemotherapy agent. The illustration shows the Michaelis–Menten curves for two asparaginases from different sources, as well as the concentration of asparagine in the environment (indicated by the arrow). Which enzyme would make a better chemotherapeutic agent?
A.Enzyme 1
B.Enzyme 2
C.Both are equally effective
D.Information is insufficient
B.Enzyme 2
Noncompetitive inhibition illustrated in a double reciprocal plot:
A. Fig. A
B. Fig. B
C. Fig. C
B. Fig. B
The vitamin required as coenzyme for the action of transaminases is
A. Niacin
B. Pantothenic acid
C. Pyridoxal phosphate
D. Riboflavin
C. Pyridoxal phosphate
Which of the following pairs of vitamin-deficiency is correct?
A. Pantothenic acid: Burning feet syndrome
B. Thiamine: Microcytic anemia
C. Cobalamin: Neural tube defects
D. Pyridoxine: Beri-beri
E. Biotin: Scurvy
A. Pantothenic acid: Burning feet syndrome
Which of the following is not true regarding enzymes?
A.They catalyze only a particular type of reaction
B.They remain active even after separation from the source
C.They are destroyed after the completion of the reaction they catalyze
D.They are irreversibly destroyed at high temperature
E.Their activity depends on the pH of the solution
C.They are destroyed after the completion of the reaction they catalyze
Which of the following is true about phosphodiester linkage?
A. 5’-phosphate group of one nucleotide unit is joined to the 3’-hydroxyl group of the next nucleotide
B. 3’-phosphate group of one nucleotide unit is joined to the 5’-hydroxyl group of the next nucleotide
C. 5’-phosphate group of one nucleotide unit is joined to the 5’-hydroxyl group of the next nucleotide
D. 3’-phosphate group of one nucleotide unit is joined to the 3’-hydroxyl group of the next nucleotide
A. 5’-phosphate group of one nucleotide unit is joined to the 3’-hydroxyl group of the next nucleotide
Which of the following statements is not true about RNA?
A. Does not have a double stranded structure
B. Thymine is present
C. Does not obey Chargaff’s rule
D.The sugar contained in RNA is a ribose
B. Thymine is present
Which of the following statements is true about the DNA?
A. The template strand matches the sequence of the RNA transcript
B. The two strands of DNA run parallel to each other
C. G-C bonds are much more resistant to denaturation than A-T rich regions
D. The common form of DNA is left handed
C. G-C bonds are much more resistant to denaturation than A-T rich regions
Which of the following involves carrying genetic information from DNA for protein synthesis?
A. m-RNA
B. t-RNA
C. r-RNA
D. sn-RNA
A. m-RNA
Which of the following is true about RNA synthesis?
A. Synthesis of RNA is always in the 5’ to 3’ direction
B. RNA polymerase requires a primer for initiating transcription
C. U is inserted opposite T in transcription
D. New nucleotides are added on the 2’-OH of the ribose sugar
A. Synthesis of RNA is always in the 5’ to 3’ direction
Which of the following mechanisms will remove uracil and incorporate the correct base?
A. Direct repair
B. Base excision repair
C. Mismatch repair
D. Nucleotide excision repair
B. Base excision repair
Which of the following statements is true?
I. In glucose, the C-1 aldehyde in the open-chain form of glucose reacts with the C-5 hydroxyl group to form an intramolecular hemiketal. II. Most natural occurring sugars belong to the D-series. III. The anomeric carbon atom in ketoses is C-2 in their cyclic forms. IV. Glycogen has more branch points formed by a-1,6 linkages than starch and thus less soluble.
A. I and II
B. II and III
C. I, II, III
D. II and IV
E. All of the above
B. II and III
Which of the following pairs are correct?
A. D-glyceraldehyde and dihydroxyacetone: enantiomers
B. D-ribose and D-ribulose: Epimers
C. a-D-glucose and b-D-glucose: Diastereomers
D. D-glucose and D-mannose: Anomers
C. a-D-glucose and b-D-glucose: Diastereomers
Which of the following statements is correct?
I. Carbohydrates are drawn as straight chains in Haworth and ring structures in Fischer projections. II. The ring forms are furanoses and pyranoses and contain 5 and 6 members, respectively.
III. In solution mutarotation occurs.
IV. a-D-glucopyranose predominates in solution
A. I and II
B. II and III
C. I, II, III
D. II and IV
E. All of the above
B. II and III
Glucose on oxidation does not give
A. Glycoside
B. Glucosaccharic acid
C. Gluconic acid
D. Glucuronic acid
A. Glycoside
The distinguishing test between monosaccharides and disaccharides is
A. Bial’s test
B. Seliwanoff’s test
C. Barfoed’s test
D. Hydrolysis test
C. Barfoed’s test
Specific test for ketohexoses:
A. Seliwanoff’s test
B. Osazone test
C. Orcinol test
D. Phloroglucinol test
A. Seliwanoff’s test
Which of the following is/are correct?
I. Glycolipids are derivative of the lipid sphingosine. II. Gangliosides are the glycolipids occurring in the liver.
III. Glycolipids are involved in intracellular communication
IV. They are produced in the endoplasmic reticulum.
A. I and III
B. II and III
C. II and IV
D. All of the above
A. I and III
The serum of an individual with B blood group contains
A. Anti-A and Anti-B antibodies
B. Anti-D antibodies
C. Anti-A antibodies
D. Anti-B antibodies
B. Anti-D antibodies
Which of the following is false about fatty acids?
A. Melting point of fatty acids decreases with increase in degree of saturation
B. Lipids in tissues that are subjected to cooling are more unsaturated
C. Naturally occurring unsaturated long-chain fatty acids are nearly trans-configuration
D. The membrane lipids contain mostly unsaturated fatty acids
C. Naturally occurring unsaturated long-chain fatty acids are nearly trans-configuration
Which of the following fatty acid has 16 carbon atoms?
A. Linolenic acid
B. Oleic acid
C. Palmitic acid
D. Stearic acid
C. Palmitic acid