Biology Quizzes Exam 2

28 Questions | Total Attempts: 240

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Biology Quizzes & Trivia

BIO 105


Questions and Answers
  • 1. 
    What defines the element to which a particular atom belongs?
    • A. 

      The number of neutrons in the nucleus.

    • B. 

      The number of protons in the nucleus.

    • C. 

      The number of electrons orbiting around the nucleus.

    • D. 

      The number of protons plus the number of neutrons in the nucleus

    • E. 

      The number of protons plus the number of electrons plus the number of electrons.

  • 2. 
    What causes a hydrogen bond?
    • A. 

      Equal sharing of electrons between oxygen and hydrogen atoms

    • B. 

      Attraction between ions

    • C. 

      Unequal sharing of electrons between covalently oxygen and hydrogen atoms

    • D. 

      A covalent bond that shares more than two electrons

  • 3. 
    Distinguish between a hydrophilic and a hydrophobic substance.    
    • A. 

      Hydrophobic substances do not mix well with water; hydrophilic substances mix well with water.

    • B. 

      Hydrophobic substances mix well with water; hydrophilic substances do not mix well with water.

    • C. 

      Hydrophobic substances form by synthesis; hydrophilic substances form by hydrolysis.

    • D. 

      Hydrophobic substances form by hydrolysis; hydrophilic substances form by synthesis.

  • 4. 
    Which general type of chemical reaction is respiration?
    • A. 

      Oxidation

    • B. 

      Reduction

  • 5. 
    Whic of the following generally describes the process of synthesis (=dehydration synthesis)
    • A. 

      Removal of -H and -OH from monomers to join the monomers into a polymer, and forming water.

    • B. 

      Using water movlcules to break polymers into monomers.

    • C. 

      The attraction of two water molecules to each other due to partial chages on each molecule.

    • D. 

      The gain of an electron as a hydrogen atom.

  • 6. 
    What does the second law of thermodynamics state?
    • A. 

      The amount of energy in the universe is constant.

    • B. 

      Energy can neither be created or destroyed.

    • C. 

      The amount of matter in the universe is constant

    • D. 

      Ome useful energy is lost to a system whenever an energy trnasfer occurs.

    • E. 

      Both 1 and 2 above are part of the second law of thermodymanics

  • 7. 
    What is the relationship between monosaccharides and polysaccharides?
    • A. 

      Polysaccharides are composed of monosaccharide units

    • B. 

      Monosarccharides are composed of polysaccharide units

    • C. 

      Monosachcarides only bond chemically to polysaccharides as side groups on the polysaccharide chain

    • D. 

      they are both sugars, but there is no other chemical relationship between them

  • 8. 
    What are the basic units that comprise an unsaturated fat molecule?
    • A. 

      Glycerol and 3 fatty acids, at leasat one of which is unsaturated

    • B. 

      1 fatty acid and 3 glycerol molecules, one of which is unsaturated

    • C. 

      a chain of carbons with some double bonds between them

    • D. 

      A bonding of amnio acids and monosaccharides

  • 9. 
    What is a secondary structure of a protein?
    • A. 

      The order of amino acids

    • B. 

      Folding and turning back on itself into a globular three-dimentional structure.

    • C. 

      Interaction of two or more separtely-formed peptide subunits to form a functioning protein unit.

    • D. 

      The twisting of the string of amino acids into an alpha-helix or pleated sheet.

  • 10. 
    Which of the following best describes an enzyme?
    • A. 

      Organic catalyst

    • B. 

      A lipid carrier molecule

    • C. 

      an inorganic catalyst

    • D. 

      A substance that is changed by a chemical reaction

  • 11. 
    What is the enzyme-substrate complex?
    • A. 

      The sum of the reactants and products of a chemical reaction

    • B. 

      The binding the substrate to the enzyme during catalysis

    • C. 

      The complex of various substrates upon which an enzyme acts

    • D. 

      a fixation on substrates by enzymes that requires deep Freudian psychotherapy

  • 12. 
    What is the active site of an enzyme?
    • A. 

      The end of the protein chain that contains "enzyme" information

    • B. 

      The place on the enzyme where energy-containing molecules bind to power the enzyme

    • C. 

      the place that binds an enzyme to the cell membrane

    • D. 

      The place on the enzyme where catalysis occurs

  • 13. 
    Why are enzymes very specific in their action?
    • A. 

      The substrate fits into the enzyme in a very specific manner

    • B. 

      The enzyme "learns" to recognize a specific substrate as it is formed and develops, but could "learn" to recognize any substrate

    • C. 

      The substrate "molds" itself to the enzyme so that any enzyme can catalyse any specific reaction

    • D. 

      The enzyme contains a copy of the substrate molecule that it uses as a "model" for the type of molecule with which it will react

  • 14. 
    What is the mechanism by which enzymes work
    • A. 

      Enzymes supply energy to the substrate for the reaction to proceed

    • B. 

      Enzymes transfer energy between substrate molecules for the reation to occur

    • C. 

      Enzymes lower the activation energy needed to begin the rection

    • D. 

      Enzymes act as a "workbench" for other molecules to carry out the reaction but have no other role

  • 15. 
    How does competitive inhibition work?
    • A. 

      A substance similar in shape to the substrate becomes permanently attached to the active site

    • B. 

      Two enzymes try to attach to the substrate and neither can

    • C. 

      Energy supplied to the enzyme does not allow it to catalyse a reaction

    • D. 

      Other substances compete with the enzyme to attach to the substrate

  • 16. 
    What happpens when an enzyme is denatured?
    • A. 

      it becomes ineffective and cannot catalyze a reaction

    • B. 

      If the enzyme is a protein, the tertiary structure is changed

    • C. 

      the shape of the active site is altered

    • D. 

      All of the above

  • 17. 
    Which of these is a coenzyme?
    • A. 

      Vitamin C

    • B. 

      Iron

    • C. 

      Cholesterol

    • D. 

      DNA

  • 18. 
    How does a noncompetitive inhibitor affect an enzyme?
    • A. 

      It constantly attaches to and detaches from the active site, blocking the substrate from the enzyme part of the time

    • B. 

      It attaches to the substrate, preventing it from interacting with the enzyme

    • C. 

      It attaches to an allosteric site, changing the shape of the active site.

    • D. 

      It causes the enzyme to become bound to a membrane

  • 19. 
    A biochemical pathway is a series of reactions within an organism that result in particular products being formed. The role of enztymes in biochemical pathways is:
    • A. 

      To identify intermediates in the pathway and independently carry them to their next destination

    • B. 

      To become intermediate products in the reaction, providing raw materials fo the next step of the reaction

    • C. 

      To provide an interconnected "bucket brigade" that passes the intermediates from point to point in the pathway

    • D. 

      Mediate each step of the reaction

  • 20. 
    What does the Cell Theory state?
    • A. 

      Organisms begin as a mass of nonliving organic materials that organize into cells spontaneously

    • B. 

      Some organisms are cellular in nature, some are not

    • C. 

      All organisms are composed of units called cells.

    • D. 

      Living things are composed fo fibrous strings called cells that weave together like cloth to form an organism.

  • 21. 
    Waht were the contributions of Rudolf Virchow in the history of cell theory?
    • A. 

      He coined the term "cell".

    • B. 

      He restated and reinforce Oken's ideas that cells come from existing cells by cell division.

    • C. 

      All organisms are cellular in nature.

    • D. 

      He was one of the first to observe and describe microorganisms as "animicules

  • 22. 
    Which of the following best describes the structure of cellular membranes according to the fluid-mozaic model?
    • A. 

      Proteins embedded in a bilayer of phospholipid

    • B. 

      Phospholipid embedded in a bilayer of proteins

    • C. 

      A bilayer of phospholipid sandwiched between an outer and an inner layer of protein

    • D. 

      A bilayer of protein sandwiched between an outer and an inner layer of phospholipid

  • 23. 
    In general, the molecules that act to carry substances across the cell membrane are
    • A. 

      Lipids

    • B. 

      Proteins

    • C. 

      Nucleic acids

    • D. 

      Carbohydrates

  • 24. 
    What is osmosis?
    • A. 

      The movement of a substance across a semipermeable membrane.

    • B. 

      Diffusion of a substance through water.

    • C. 

      Diffusion of water across a semipermeable membrane.

    • D. 

      Diffusion of water within a solution.

  • 25. 
    What is the function of the nucleus?
    • A. 

      Information storage for cell metabolism and heredity

    • B. 

      Processing energy from food

    • C. 

      Packaging and transport of materials for export from the cel

    • D. 

      Intracellular digestion of foodstuffs

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