Functional groups are really important in organic reactions. They change how organic compounds behave and react. These groups play a big role in how molecules bond and change, which leads to many different reactions.

1. Reactivity:

   • Functional groups help decide how reactions happen, like nucleophilic substitution or electrophilic addition.
   • For example, alkyl halides (like R-X) can react faster than normal alkanes, sometimes over a million times faster!

2. Types of Functional Groups:

   • Some common functional groups are hydroxyl ($-OH$), carbonyl ($C=O$), and carboxyl ($-COOH$).
   • Each group has its own special features that greatly change how reactions occur.

3. Statistics:

   • More than 80% of organic reactions involve changes in functional groups.
   • When studying organic reactions, knowing about functional groups can help predict what will happen in up to 95% of cases.