Common Biochemical Reactions

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Common Biochemical Reactions
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chemical reaction

• a process involving one, two or more substances
  (called reactants), characterized by a chemical
  change and yielding one or more product(s) which
  are different from the reactants

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chemical change

• molecules attaching to each other to form larger
  molecules, molecules breaking apart to form two,
  or more, smaller molecules, or rearrangement of
  atoms within molecules

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chemical change

• involve the making or breaking of chemical bonds
• does not change the nucleus of the atom in any
  way, only the interaction of the electron clouds
  of the involved atoms
• Nuclear reactions are not considered chemical
  reactions, although chemical reactions may follow
  a nuclear transformation.

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Types of chemical reaction

• Synthesis, where two or more compounds unite to
  form a more complex product

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Types of chemical reaction

• Chemical decomposition, where a substance is
  decomposed into smaller compounds
• Combustion, where a substance reacts with oxygen
  gas

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Types of chemical reaction

• Single displacement reaction, also called a
  single replacement reaction, characterized by an
  atom of an element which is part of a compound
  being displaced out of it by a more reactive atom

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Types of chemical reaction

• Double displacement reaction, also called a
  double replacement reaction, where compounds
  (usually ionic) exchange ions to form different
  compounds

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Types of chemical reaction

• Acid-base neutralization, where an acid and an
  base react producing water

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Types of chemical reaction

• organic reactions, which encompass several
  different kinds of reactions involving compounds
  which have carbon as the main element in their
  molecular structure.

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Types of chemical reaction

• redox reactions, which involve electron
  transference between compounds (metallic single
  displacement and combustion are two common
  examples)
• acid-base reactions

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Nucleophilic Substitution Reactions 

• replacement of one  atom or group with a
  different nucleophilic atom or group

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Nucleophilic Substitution Reactions 

• Generally anions or unshared electron pairs

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Common biological nucleophiles

• oxygen, nitrogen, and sulfur

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Hydrolysis Reactions

• a common class of nucleophilic substitution
• Addition of water to break a covalent bond
• Hydrolysis of ATP

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Elimination Reactions

• removal of atoms to form a double bond
• Dehydration removal of water (e.g. from a C - C
  bond to form a C C double bond

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Addition Reactions

• combining two molecules to form a single product
  (generally across a C C double bond)
• Hydration  Addition of water (e.g. to a C C
  double bond)
• Ex. a late step in the Krebs Cycle

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Isomerization Reactions

• intramolecular rearrangement of atoms or groups
  (e.g. isomerization of sugar molecules

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Oxidation-Reduction Reactions

• transfer of electrons from a donor (reducing
  agent) to an acceptor molecule (oxidizing agent)
• Reduction gain of electrons
• gain of Hydrogen or loss of Oxygen
• Oxidation  loss of electrons
• gain of Oxygen or loss of Hydrogen
• Note  Oxidation and Reduction are coupled
  reactions (REDOX)