ENZYMES

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ENZYMES
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What is an enzyme?

• Protein
• Long chain of amino acids
• Very specific 3-D shape, globular
• Active site for substrate (glove or lock)
• Usually end in -ase

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Role of Enzymes

• Almost all metabolic reactions in organisms are
  catalyzed by enzymes
• Influence rate of reactions
• Lowers activation energy

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Metabolism

• Sum of all chemical reactions
• Anabolism
• Endergonic absorb energy, photosynthesis
• Catabolism
• Exergonic release energy, respiration

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Energy Transfer in Chemical Reactions

• You will learn of many examples in human
  metabolism that involve coupled exergonic and
  endergonic reactions the energy released from
  one reaction will drive the other.

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Factors influencing reactions

• Concentration
• Temperature
• Why do these factors not work well in living
  organisms?
• High temperatures would kill the cell and heat
  would speed up all reactions, enzymes solve both
  problems

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Enzymes solve problems

• Speed up chemical reactions by lowering the
  activation energy needed for a reaction to occur.
• Helps to orient colliding particles so reaction
  can occur
• The catalyst itself is unchanged at the end of
  the reaction it is often re-used many times.

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Activation Energy

• Atoms are continuously moving colliding.
• Activation energy is the collision energy needed
  to break bonds begin a reaction.
• Increases in concentration temperature,
  increase the probability of collision

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Enzyme Functionality

• Highly specific
• Very efficient
• speed up reaction up to 10 billion times faster
• Under control
• rate of synthesis
• inhibitory substances