Enzymes allow chemical reactions to occur under tightly controlled

							    Enzymes
Explain how enzymes function as
           catalysts.
  A catalyst lowers activation energy.

• Activation energy for a chemical reaction is the
  amount of energy needed to get a reaction started.
  Once the reaction starts, it can continue by itself,
  and it will go at a certain rate.
• A catalyst is a substance that decreases activation
  energy needed to start a chemical reaction, and as a
  result, also increases the rate of the chemical
  reaction.
  Enzymes allow chemical reactions to
  occur under tightly controlled
  conditions.
• Chemical reactions in organisms have to take place
  at an organism’s body temperature.
• Enzymes are catalysts for chemical reactions in
  living things.
  – Enzymes lower activation energy and increase the rate
    of chemical reactions.
  – Enzymes are involved in almost every process in
    organisms.
     • Breaking down food
     • Building proteins
  Enzymes allow chemical reactions to
  occur under tightly controlled
  conditions.
• Almost all enzymes are proteins.
  – Made of long chains of amino acids
  – Depends on its structure to function properly
  – Conditions such as temperature and pH can affect the
    shape and function, or activity, of an enzyme.
  Enzymes allow chemical reactions to
  occur under tightly controlled
  conditions.
• Enzyme structure is important because each
  enzyme’s shape allows only certain reactants to
  bind to the enzyme.
  – Specific reactants that an enzyme acts on are called
    substrates.
     • Substrates temporarily bind to enzymes at specific
       places called active sites.
     • Substrates fit the exact active sites of enzymes like a
       lock and key. (Lock and Key Model)
Substrates bind to     The enzyme brings      The catalyzed
  an enzyme at             substrates        reaction forms
  certain places         together and       a product that is
called active sites.     weakens their          released
                             bonds.        from the enzyme.