How does smoking damage the DNA of cells, and what signals are either inhibited or sent as ‘wrong’?

Question: How does smoking damage the DNA of cells, and what signals are either inhibited or sent as 'wrong'?

Asked by snacks2 to Kay on 22 Mar 2010 in Categories: Theories.
- Kay Penicud answered on 23 Mar 2010:
  
  Smoking contains chemicals. These can have chemical reactions with your DNA, changing its structure and the bases (A, T, G, C) so as you end up with a mutated gene – which makes a mutated protein, or too much, or too little protein.
  
  These signals are mainly involved in cell growth. So you would inhibit signals that normally stop the cell from dividing too much, and sent signals that are not supposed to be sent – e.g. for cells to divide lots, or too move around the body (when cancer spreads) or for cells not to die when they are supposed to

Question: How does smoking damage the DNA of cells, and what signals are either inhibited or sent as 'wrong'?