Chemical Reactions and Enzymes Notes

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Chemical Reactions and Enzymes Notes
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Objectives

• What happens to chemical bonds during chemical
  reactions?
• Explain the effect of a catalyst on activation
  energy.
• Why are enzymes important to living things?

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Vocabulary

• Chemical reaction
• Reactant
• Product
• Activation energy
• Catalyst
• Enzyme
• Substrates

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Chemical Reaction

• A process that changes, or transforms, one set of
  chemicals into another.

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Reactants

• The elements or compounds that enter into a
  chemical reaction.

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Products

• The elements or compounds produced by a chemical
  reaction.

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• Chemical reactions always involve changes in the
  chemical bonds that join atoms in compounds.

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Activation Energy

• The energy that is needed to get a reaction
  started.

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Catalyst

• A substance that speeds up the rate of a chemical
  reaction.

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Enzymes

• Proteins that act as biological catalysts.

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• Enzymes speed up chemical reactions that take
  place in cells.

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• The micrograph shows a white blood cell engulfing
  an invading pathogen.
• (Colored SEM magnification about 3000X)

The larger micrograph shows a pathogen after it
has been captured. Once inside a white blood
cell, enzymes are used to destroy the
pathogen. (Colored TEM magnification 11,000X)
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Substrates

• The specific reactants that an enzyme acts on.

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• Substrates bind to an enzyme at certain places
  called active sites.
• The enzyme brings substrates together and weakens
  their bonds.
• The catalyzed reaction forms a product that is
  released from the enzyme.

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• Enzymes are proteins that catalyze biochemical
  reactions. The activities of enzymes depend on
  the temperature, ionic conditions, and the pH of
  the surroundings.