Unit 3 Biochemistry Multiple IB Exam Questions

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Unit 3 Biochemistry Multiple IB Exam Questions

Biochemistry, or biological chemistry, is the study of chemical processes within and with regards to living things. This includes such topics as metabolism, and concerns all kinds of organisms from bacteria to us human beings.


Questions and Answers
  • 1. 
    Which molecule represents ribose?
    • A. 

      A

    • B. 

      B

    • C. 

      C

    • D. 

      D

  • 2. 
    Which of the following reactions occurs when a dipeptide is formed from amino acids?
    • A. 

      Hydrolysis

    • B. 

      Denaturation

    • C. 

      Condensation

    • D. 

      Oxidation

  • 3. 
    Which is not a primary function of protein molecules?
    • A. 

      Hormones

    • B. 

      Energy store

    • C. 

      Transport

    • D. 

      Structure

  • 4. 
    Which structure represents an amino acid?
    • A. 

      A

    • B. 

      B

    • C. 

      C

    • D. 

      D

  • 5. 
    • A. 

      I and II only

    • B. 

      II and III only

    • C. 

      III and IV only

    • D. 

      I and IV only

  • 6. 
    • A. 

      The pectin content of the fruit is increased, making the nutritional value of the juice higher.

    • B. 

      The pectin content of the fruit is reduced, making the energy content of the juice lower.

    • C. 

      The pectin content of the fruit is reduced, making the juice easier to extract.

    • D. 

      The pectin content of the fruit is increased, giving the juice a thicker texture.

  • 7. 
    Which of the following could cause denaturation of an enzyme?
    • A. 

      Substrate concentration

    • B. 

      A competitive inhibitor

    • C. 

      High temperature

    • D. 

      Low salt concentration

  • 8. 
    What is the composition of the backbone of DNA?
    • A. 

      Alternating sugar and phosphate molecules

    • B. 

      Complementary base pairs

    • C. 

      Alternating sugar and base molecules

    • D. 

      A polysaccharide

  • 9. 
     Which of the following are connected by a hydrogen bond?
    • A. 

      The hydrogen and oxygen atoms of a water molecule

    • B. 

      A base pair of a DNA molecule

    • C. 

      Two amino acid molecules of a dipeptide

    • D. 

      Two glucose molecules in a disaccharide

  • 10. 
     What is the function of helicase?
    • A. 

      It forms bonds between DNA nucleotides.

    • B. 

      It adds new nucleotides to the DNA helix.

    • C. 

      It forms the DNA helix.

    • D. 

      It separates DNA strands.

  • 11. 
    • A. 

      II and III only

    • B. 

      I and III only

    • C. 

      I and II only

    • D. 

      I, II, III and IV

  • 12. 
     What is removed to form mature eukaryotic mRNA?
    • A. 

      RNA primers

    • B. 

      Exons

    • C. 

      RNA polymerases

    • D. 

      Introns

  • 13. 
     A certain gene codes for a polypeptide that is 120 amino acids long. Approximately how many nucleotides long is the mRNA that codes for this polypeptide likely to be?
    • A. 

      30

    • B. 

      40

    • C. 

      360

    • D. 

      480

  • 14. 
    Where do transcription and translation occur in eukaryotic cells?
    • A. 

      Both in the cytoplasm

    • B. 

      Transcription in the cytoplasm, translation in the nucleus

    • C. 

      Transcription in the nucleus, translation in the cytoplasm

    • D. 

      Both in the nucleus

  • 15. 
     Of the following products, which is produced by both anaerobic respiration and aerobic respiration in humans?I - PyruvateII - ATPIII - Lactate
    • A. 

      I only

    • B. 

      I and II only

    • C. 

      I, II and III

    • D. 

      II and III only

  • 16. 
    What is needed in photosynthesis to convert carbon dioxide into organic molecules?
    • A. 

      Light and hydrogen from the splitting of water

    • B. 

      Light and oxygen from the splitting of water

    • C. 

      ATP and hydrogen from the splitting of water

    • D. 

      ATP and oxygen from the splitting of water

  • 17. 
     Pigments are extracted from the leaves of a green plant. White light is then passed through the solution of pigments. What effect do the leaf pigments have on the white light?
    • A. 

      Green wavelengths are absorbed and red and blue wavelengths are transmitted.

    • B. 

      Red and blue wavelengths are absorbed and green wavelengths are transmitted.

    • C. 

      Blue wavelengths are absorbed and green and red wavelengths are transmitted.

    • D. 

      Green and red wavelengths are absorbed and blue wavelengths are transmitted.

  • 18. 
    One of the roles of nitrogen in living things is
    • A. 

      In the production of amino acids

    • B. 

      In the production of carbohydrates

    • C. 

      In the production of lipids

    • D. 

      In all of the above

  • 19. 
     Water molecules are described as being dipolar. This means that
    • A. 

      It has one oxygen atom and two hydrogen atoms

    • B. 

      It has one hydrogen atom and two oxygen atoms

    • C. 

      It has negative and positive "ends"

    • D. 

      It has two negative "ends"

  • 20. 
     The sugar lactose is composed of
    • A. 

      Two glucose molecules

    • B. 

      One glucose and one sucrose molecule

    • C. 

      One glucose and one galactose molecule

    • D. 

      One galactose and one sucrose molecule