Million of bacteria grow in our gut and each have their own set of genes , that helps them to survive acidic environment of the gut. They can have both beneficial and harmful effect to your health.
While the bacteria in lungs causes symptoms similar to the cold or flu, it can be more severe and typically last longer. Immune system will typically be able to clear a viral lung infection over time. Infections can be cured by using antibiotics also .
On the other hand bacteria on skin can survive up to 20 minutes .Human skin also act as barrier that limits invasion and growth of pathogenic bacteria. Human body has a lot of defenses to keep the bad bacteria from coming in too far through these openings.
One of the three phosphate groups on the ATP are released to form ADP leaving it with two phosphate groups. Breaking down this ATP releases energy to be used by the cell.