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).
Chemiosmosis: Electron transport provides energy for the synthesis of ATP, but only indirectly. When electron transport chains pump H+ across the membrane, the protons become more concentrated on one side of the membrane than on the other. Such a concentration gradient stores potential energy. ATP is generated by a molecule called ATP synthase. ATP synthase is a combination of proteins that act as both an ion channel and an enzyme. As an ion channel in the membrane of the mitochondria or thylakoids, it allows H+ to diffuse through it. This action spins a component of the ATP synthase. This rotation activates the active sites in the enzyme that attach phosphate groups to ADP molecules to generate ATP. 21.