Mechanisms

• What are nucleophiles characterized by?

  Electron-rich species with negative charge
• What defines an electrophile?

  Electron-poor species with positive charge
• What is the result of a reaction between a nucleophile and an electrophile?

  A new covalent bond is formed
• What does a curly arrow represent in a reaction mechanism?

  Movement of a pair of electrons

  
• What happens during the protonation of methoxide ion?

  Methanol is formed from methoxide ion
• What is the role of hydroxide ion in nucleophilic reactions?

  It acts as a basic nucleophile

  
• Which of the following is NOT a nucleophile?

  Amides
• What type of compounds are considered reactive electrophiles?

  Aldehydes and ketones
• What is the least reactive carbonyl-containing compound?

  Amides
• What are the steps in drawing curly arrows for a reaction mechanism?

  1. Identify nucleophile and electrophile
  2. Show electron movement with arrows
  3. Ensure charge balance on both sides

  
• What is the first step in the reaction between ethanoyl chloride and ethylamine?

  Nucleophilic attack by ethylamine

  
• What occurs during the elimination stage of the reaction?

  A chloride ion is expelled
• What is an SN2 reaction characterized by?

  Nucleophilic substitution at sp3 carbon

  
• What does SN2 stand for?

  Substitution nucleophilic bimolecular
• In an SN2 reaction, how does the nucleophile approach the electrophile?

  From behind the carbon atom
• What are the two phases of chymotrypsin's catalytic action?

  1. Acylation phase
  2. Deacylation phase
• What is the role of the catalytic triad in chymotrypsin?

  Enhances the nucleophilicity of serine
• Which amino acids does chymotrypsin cleave next to?

  Large hydrophobic or aromatic amino acids
• What happens when water enters the chymotrypsin reaction?

  It participates in the hydrolysis reaction
• What is released during the reaction catalyzed by chymotrypsin?

  Amine and acid