People who are infected with HIV do not get sick immediately. It can take the body months to attempt to fight off the virus and for a patient to test HIV-positive. So, paradoxically, the period when an HIV-positive person is most infectious coincides with the period he or she is least likely to know their status.
The ATP synthase of mitochondria and chloroplasts is an anabolic enzyme that harnesses the energy of a transmembrane proton gradient as an energy source for adding an inorganic phosphate group to a molecule of adenosine diphosphate (ADP) to form a molecule of adenosine triphosphate (ATP).
ATP works by losing the endmost phosphate group when instructed to do so by an enzyme. This reaction releases a lot of energy, which the organism can then use to build proteins, contact muscles, etc. The reaction product is adenosine diphosphate (ADP), and the phosphate group either ends up as orthophosphate (HPO 4) or attached to another molecule (e.g. an alcohol).