Sample topic sentences
Free Radicals and Antioxidants

1. Intro: raises topic strings:
   • biological activity associated with free radicals
   • antioxydants counter free radicals
      
     
2. In biological systems, all atoms consist of nucleus surrounded by four lobs of electrons; bonding and chemical activity occurs through these lobs.
    
   
3. Free radicals are atoms that have an odd number of electrons in one of their lobs; they are unstable and highly reactive.
    
   
4. In biological systems, most common free radical is the oxygen radical.
    
   
5. The oxidizing effect of the oxygen radical makes it harmful to living organisms.
    
   
6. Our bodies produce free radicals, especially when we are active.
    
   
7. Free radicals are also produced by outside influences: radiation, heavy metals and some medical treatments (e.g., chemotherapy).
    
   
8. Molecular damage by free radicals can be prevented by antioxidants.