Enzymes

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Enzymes

• The protein catalyst of life

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Enzymes The Video Clip
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Enzyme Vocabulary

• Enzymes end in ase
• Maltase binds to maltose
• Lactase binds to lactose
• Lipase breaks down fat
• Amylase is found in saliva
• Catalyst
• Substance that affects the rate of a chemical
  reaction WITHOUT BEING ALTERED
• Because it is not altered, can do same thing
  over, and, over, and, over, and over.
• Enzymes are ORGANIC CATALYSTS

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Enzyme Vocabulary

• Substrate
• The substance upon which the enzyme reacts
• Active site
• Site where enzyme binds to substrate
• Denature
• When enzymes shape is altered due to
• high temp
• strong acids or bases

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How Do Enzymes Work?
DEMO
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Importance of Enzyme Shape

• Enzymes have specific shapes
• This means enzymes are specific to their
  substrate
• They will only attach to substrate that fits
  their shape
• If shape of enzyme is denatured, will it be able
  to bind to its substrate?
• NO!
• Two things can cause denaturing
• Temperature
• pH

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Denaturing or Mutation of Enzyme The Video Clip
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Enzyme-Substrate Complex

• Formed when enzyme binds to substrate
• Very specific
• Lock and Key Model
• Enzyme-substrate complex often compared to a lock
  and key
• Active site on enzyme can only FIT or bind to a
  
• specific substrate
• Example Amylase will bind to starch, but not
  cellulose

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Enzyme-substrate Complex
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The Enzyme Jingle!SUNG TO JINGLE BELLS!

• Shape, Shape, Shape
• Shape, Shape, Shape
• Enzymes have a shape
• If active site is denatured
• It wont bind suuu-uuuub-stra-ate
• Shape, shape, shape
• Shape, shape, shape
• Enzymes have a shape
• Wrong pH or temperature
• Will affect its shape

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What affects Enzyme Reaction Rates?

• Remember, enzymes speed up reactions
• What can affect the rate at which enzymes
  perform?
• Its shape!
• Denaturing affects rate
• The amount of enzyme and substrate!

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Enzyme shape and reaction rate Temperature

• Enzymes have a specific temperature range at
  which they work best
• EX. Human enzymes work best at 37C
• Temps not in the optimal range will cause enzymes
  to denature
• Shape is altered, so reaction rates are SLOWED or
  stopped altogether
• Reaction rates will DROP dramatically depending
  on how much denaturing of enzyme DEMO

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Temperature vs. Reaction Rate
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Enzyme shape and reaction rate pH

• Enzymes have a specific pH range at which they
  work best
• EX. Most enzymes work best at pH 7
• Where in the body would enzymes be optimal at a
  low (acidic) pH? Why?
• In stomach. This is because stomach acid has a
  low pH
• pH not in the optimal range will cause enzymes to
  denature
• Shape is altered, so reaction rates are SLOWED or
  stopped altogether
• Reaction rates will DROP dramatically depending
  on how much denaturing of enzyme DEMO

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pH vs. Reaction Rate
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Enzyme amount and reaction rate

• Enzyme rate also depends on the amount of enzyme
  and substrate
• Little enzyme, lots o substrate
• Slower rates
• How can we speed up the rate?
• Add more enzyme until max. rate achieved.

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Substrate Concentration vs. Reaction Rate