Biochemistry - Med Exam

44 Questions

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Biochemistry Quizzes & Trivia

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Questions and Answers
  • 1. 
    Match the correct pair:
    • A. 

      Catabolism:Reduction

    • B. 

      Anabolism:Oxidation

    • C. 

      Catabolism:Oxidation

    • D. 

      Anabolism:Oxidation and reduction

  • 2. 
    If gibbs free energy for a specific reaction is negative, that means?
    • A. 

      The direction of reaction is backward

    • B. 

      The direction of reaction is forward

    • C. 

      The reaction is in equlibruim

    • D. 

      We cant determine the direction

  • 3. 
    Some examples of amphiphilic membrane lipids:
    • A. 

      Ethanol Amine

    • B. 

      Sphingolipids

    • C. 

      Glycerophospholipids

    • D. 

      B+C

  • 4. 
    H3PO4 is?
    • A. 

      Monoprotic : 3pKa values

    • B. 

      Triprotic : 3 pKa values

    • C. 

      Monoprotic : 1pKa value

    • D. 

      Monoprotic : 2pKa value

  • 5. 
    In Henderson Hasselbalch equation?
    • A. 

      PH and pKa are variables

    • B. 

      PH is constant and pKa is variable

    • C. 

      PH is variable and pKa is constant

    • D. 

      Both are constants

  • 6. 
    _____ is present in the active site of enzymes?
    • A. 

      Proline

    • B. 

      Valine

    • C. 

      Cysteine

    • D. 

      Glutamate

  • 7. 
    The only amino acid which has its R group attached to its alpha amino group?
    • A. 

      Glyceine

    • B. 

      Phenylalanine

    • C. 

      Trypotophan

    • D. 

      Proline

    • E. 

      B+C

  • 8. 
    Sicke cell disease is a change in?
    • A. 

      Primary structure

    • B. 

      Secondary structure

    • C. 

      Tertiary structure

    • D. 

      All of the above

  • 9. 
    To measure the concentration of proteins in biological fluids, we use?
    • A. 

      Spectrophotometer

    • B. 

      Beer's law

    • C. 

      Spectrophotometer + Beer's law

    • D. 

      We cant measure them

  • 10. 
    How many pKa values we have in the following cyclic polypeptide chain,(Val-Pro-Ser-Tyr-Glu)
    • A. 

      3

    • B. 

      5

    • C. 

      1

    • D. 

      2

  • 11. 
    Which of the following characterized by Carboxiamide group?
    • A. 

      Gln

    • B. 

      Asn

    • C. 

      Glu+Asn

    • D. 

      Gln+Asn

    • E. 

      Gln+Asp

  • 12. 
    Carboxamide group is considered polar because?
    • A. 

      It can be ionized in high pH

    • B. 

      It can be ionized in low pH

    • C. 

      It can be ionized and can make H-Bonds

    • D. 

      Its not ionizable but it can form H-Bonds

  • 13. 
    Which of the following is correctly paired
    • A. 

      Arginine:Guanidino

    • B. 

      Lysine:Epsilon Amine group

    • C. 

      Histidine:Amine group in ring

    • D. 

      All are correct

  • 14. 
    At physiological pH which of the following will be titrated ?
    • A. 

      Arginine

    • B. 

      Histidine

    • C. 

      Lysine

    • D. 

      Tyrosine

  • 15. 
    Which of the following has a function in carrying fatty acids for oxidation?
    • A. 

      Carnitine

    • B. 

      Ornithine

    • C. 

      Citrulline

    • D. 

      Ornithine + Citrulline

  • 16. 
    Which of the following is the wrong sentence?
    • A. 

      PH value will change the active site of an enzyme

    • B. 

      Selenium in Selenocysteine is an anti-oxidant

    • C. 

      Non-Protein amino acids can participate in protein synthesis in some cases

    • D. 

      Pyrrolysine is not genetically coded

  • 17. 
    Which of the following amino acids participate in urea cycle ?
    • A. 

      Carnitine

    • B. 

      Ornithine

    • C. 

      Citrulline

    • D. 

      Ornithine + Citrulline

  • 18. 
    The precentage of Proline in Copllagen is ?
    • A. 

      20%

    • B. 

      50%

    • C. 

      30%

    • D. 

      No Proline in it.

  • 19. 
    The modification from proline to hydroxyproline is ?
    • A. 

      Post-Transational

    • B. 

      Pre-Transational

    • C. 

      Post-Transcriptional

    • D. 

      Pre-Transcreiptional

  • 20. 
    Peptide bond is formed between?
    • A. 

      Alpha Amino - Alpha carbon

    • B. 

      Alpha Carboxyl - Alpha carbon

    • C. 

      Alpha Amino - Alpha carboxyl

    • D. 

      A+B

  • 21. 
    Choose the correct statement :
    • A. 

      Phosphorylation activates proteins

    • B. 

      Phosphorylation deactivates proteins

    • C. 

      Phosphorylation can activate or deactivate a specific protein

    • D. 

      Phosphorylation has nothing to do with activating

  • 22. 
    Hydroxyproline function to collagen?
    • A. 

      Chemical stability

    • B. 

      Thermal Stability

    • C. 

      Packing its amino acids close together

    • D. 

      Denaturate it when un-needed

  • 23. 
    What Catalyize the synthesizing of a polypeptide bond in eukaryotes ?
    • A. 

      28 sRNA

    • B. 

      23 sRNA

    • C. 

      Ribosomes

    • D. 

      All of the above

  • 24. 
    Secondary structures include?
    • A. 

      Alpha helix

    • B. 

      Beta sheets

    • C. 

      Beta turns

    • D. 

      All of the listed

  • 25. 
    In secondary structure, the interactions are between?
    • A. 

      Side chains

    • B. 

      Backbons + Side chains

    • C. 

      Backbone

    • D. 

      Terminal groups only

  • 26. 
    Fibrous proteins are?
    • A. 

      Primary structure only

    • B. 

      Primary and secondary structures

    • C. 

      Primary, secondary and quaternary structures

    • D. 

      Primary, Secondary and Tertiary structures

  • 27. 
    What prevent the collagen from forming alpha helixes or beta sheets?
    • A. 

      The tempreature of body

    • B. 

      Presence of Proline in it

    • C. 

      It's long sequence

    • D. 

      The pH of the body

  • 28. 
    Glyceine importance in Collagen arises from?
    • A. 

      Making disulfide bonds to stabilize it

    • B. 

      Packing it tightly with minimal space

    • C. 

      Creating Metallic bonds with neigboring strands

    • D. 

      Glyecine isn't present in Collagen

  • 29. 
    Classification of Fibrion, precentage of Glyecine in it?
    • A. 

      Fibrous,1/3

    • B. 

      Globular,1/3

    • C. 

      Globular,1/2

    • D. 

      Fibrous,1/2

  • 30. 
    All of the following are related to column chromatography except :
    • A. 

      A-charge

    • B. 

      Size

    • C. 

      PI

    • D. 

      Affinity

    • E. 

      Polarity

  • 31. 
    Which of the following techniques is used to break the connective tissue fibers ?
    • A. 

      Homogenization

    • B. 

      Centrifugation

    • C. 

      Ultra-sonication

    • D. 

      Dialysis

  • 32. 
     Reverse phase chromatography is separation based on :
    • A. 

      Charge

    • B. 

      Size

    • C. 

      Affinity

    • D. 

      Polarity

  • 33. 
     In agarose gel electrophoresis we stain the Dna by a fluorescent stain called :
    • A. 

      Sodium dodecyl sulfate

    • B. 

      Ethidium bromide

    • C. 

       Auramine Rhodamine

    • D. 

      Haematoxylin

    • E. 

      Acid fuchsine

  • 34. 
    When delta G is -ve it means that the reaction :
    • A. 

       will happen very fast.  

    • B. 

      Will happen slowly

    • C. 

      Will happen spontaneously

    • D. 

      Non of the above

  • 35. 
    Enzymes speed up the reaction by:
    • A. 

      Lowering the energy of reactants

    • B. 

       lowering the energy of the products

    • C. 

      Lowering the transitional energy

    • D. 

      2 answers are correct

  • 36. 
    What is wrong about enzymes:
    • A. 

      They accept any isomer of the same structure

    • B. 

      They're the most efficient catalysts

    • C. 

       the active site has a binding site and a catalytic site

    • D. 

      They are very specific to a substrate

  • 37. 
    In zero order kinetics:
    • A. 

       increasing the concentration of enzyme, increases the Vmax

    • B. 

       increasing the concentration of substrate, increases the Vmax

    • C. 

      The Km will increase by increasing the concentration of substrate

    • D. 

      The velocity of the reaction will depend on one specific substrate

  • 38. 
    The committed step is :
    • A. 

      Shunting to other pathways isn't possible.

    • B. 

      Must be irreversible

    • C. 

      Delta G is highly -ve

    • D. 

      All of the above

  • 39. 
    All of the following increase the rate of a rxn, except:
    • A. 

      Increasing the substrate concentration in 1st order.

    • B. 

       increasing the concentration of a product will increase the the activity of the committed step

    • C. 

      Increasing the temp, to a point

    • D. 

      Non of the above

  • 40. 
    In ETC all the enzyme complexes, which is wrong :
    • A. 

      Oxidized ready to accept e-.

    • B. 

      Reduced ready to accept e-

    • C. 

      Inhibiting one step will inhibit all steps and wont produce atp

    • D. 

      They are coupled rxns

  • 41. 
    Which statement is wrong ?
    • A. 

      Carbohydrates can be used as source of energy and as form of storing energy.

    • B. 

      Used in intercellular communications and in ABO blood grouping

    • C. 

      One gram of proteins gives the same amount of energy as one gram of carbs

    • D. 

      Can be used to make ketone bodies in starvation

  • 42. 
    The types of bonds in cellulose are:
    • A. 

      α-1,4 glycosidic bond & α-1,6 glycosidic linkages  

    • B. 

      α-1,4 glycosidic linkages & β-1,4 glycosidic linkages

    • C. 

      β-1,4 glycosidic linkage & hydrogen bonds

    • D. 

       β-1,4 glycosidic linkage & β-1,6 glycosidic linkages

  • 43. 
    Which statement is wrong about glycolysis:
    • A. 

      Produces 2ATP & 2NADH

    • B. 

       2 phases the invesment the payoff

    • C. 

      Has a couple of major regulatory sites throughout the pathway

    • D. 

      The enzyme catalyzing the 3rd step is the aldolase enzyme

  • 44. 
    Which doctor is gonna make you cry tomorrow ?? 
    • A. 

      Alfaqih

    • B. 

      Albashir

    • C. 

      Nobody can make me Cry xD

    • D. 

      None of the above