Enzymes

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Enzymes

• Observing the Effects of Biological Catalysts

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Schedule for Today
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What is an Enzyme?

• Enzymes are biological catalysts.
• biological composed of protein
• or, rarely, RNA
• catalyst speeds up a reaction
• without being changed
• by the reaction

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How Do They Work?

• Enzymes combine with reactants (substrates) and
  promote favorable conditions for converting them
  to products.
• Enzymes speed up biological reactions by lowering
  the activation energy for the reaction.

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Properties of Enzymes

• Three dimensional structure of an enzyme
  preserves its ACTIVE SITE
• active site region on enzyme where
• reactants bind
• Conditions that can affect three dimensional
  structure include heat, pH (acid/base balance)
  and other chemicals (salt, charged ions)

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Effects of Temperature and pH on Enzymatic
Activity
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Cheese Making
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Tube Composition for Bile and Fat Digestion
Add reagents in any order. Incubate all tubes at
37oC for at least 1 hour.
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Fat Digestion
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Tubes before 37oC Incubation
Tubes after 37oC Incubation
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CLEAN UP!

• Rinse glassware, use detergent and test tube
  brush to clean thoroughly
• Leave clean test tubes inverted in the rack at
  your station
• Collect cheese solids carefully so that they do
  not fall into the sink
• Discard cheesecloth and cheese solids in trash
• Make sure the sinks stay clean

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Worksheet

• Complete pages 51-52 from lab manual
• Be sure your instructor checks your completed
  worksheet before you leave the lab