Antibiotics in Action

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    Chemistry Activity
    Enzyme Specificity
    Adventures in Digestion

    Major Chemical Concept

    The activity's main concept is how enzymes facilitate reactions that would be not otherwise take place. Students should understand that as catalysts, enzymes do not alter the thermodynamics of a reaction, but only alter the kinetics of the reaction. Enzymes speed up the reaction rate by lowering the activiation energy. Students also should understand that all life depends on the functioning of enzymes to catalyze biologically important reactions.
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      General Safety Guidelines
      Major Chemical Concept
      Materials and Apparatus

        Activity #1: Digestion of
        Protein by Tripsin
        Activity #2: Digestion of
        Lipids by Lipase
        Activity #3: Digestion of
        Starch by Amylase
        Preparation of
        Pancreatin Solution
      Relevant National Science
      Education Standards
      Relevant New Jersey State
      Science Education Standards

    Materials and Apparatus

    Lab #1: Digestion of Protein by Tripsin

    • Pancreatin solution (see formula)
    • Liquid gelatin (see formula)
    • Ice
    • 10-ml pipette, bulb
    • 10-ml graduated cylinder
    • Test tubes (25 x 200) with white marking patch

    Lab #2: Digestion of Lipids by Lipase

    • Vegetable oil, whole milk, or fresh cream
    • Pancreatin solution (see formula), a source of lipase
    • Bile salts
    • Phenol red solution or phenolphthalein (pH indicator solution)
    • Beral pipettes
    • Thermometer
    • Distilled water
    • 3 test tubes (18 x 150) with white patch for marking
    • Test tube rack

    Lab #3: Digestion of Starch by Amylase

    • 11 test tubes with white patch for marking (15 x 150)
    • Test tube holder
    • Thermometer
    • Funnel, support, and filter paper
    • Unsweetened saltine cracker
    • Benedict's or Fehling's solution
    • Iodine solution (I2/KI)
    • Hydrochloric acid solution (pH 3 and 6, or 1x10-3M and 1x10-6M)
    • Sodium hydroxide solution (pH 8 and 11, or 1x10-6M and 1x10-3M)
    • Hot water bath (electric hot plate or pot)
    • 7 beakers, 250 ml
    • Glass stirring rod
    • pH test paper
    • Starch solution (prepared by adding spray starch to warm water in a beaker)

    Preparation of Pancreatin Solution

      Dissolve the following in 100 cm3 of distilled water:

    • 1 g pancreatin
    • 1 cm3 CaCl2 ( 1 % solution)
    • 25 cm3 K2HPO4 (0.2 M solution)
    • 11.8 cm3 NaOH (0.2 M solution)

    Relevant National Science Education Standards

      Unifying Concepts and Processes — The activity is concerned with the interaction of enzymes and substrates in biological systems, involves searching for evidence of enzymatic activity, and observation of changes induced by enzyme activity.

      Science as Inquiry — The activity involves conducting systematic observations, interpreting and analyzing data, drawing conclusions, and communicating results.

      Physical Science — The activity involves chemical reactions catalyzed by enzymes.

      Life Science — The activity is concerned with the chemical behavior of matter in living systems.

    Relevant New Jersey State Science Education Standards

      5.1 The activity involves conducting systematic observations, interpreting and analyzing data, drawing conclusions, and communicating results.
      5.5 The activity illustrates the function of enzymes, essential to all life.
      5.6 The activity investigates the behavior of enzymes and substrates.

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