Answer:
e. PhoU keeps PhoR bound to the phosphate transporter protein Pst
Explanation:
PhoU is a membrane protein known to regulate the transport of phosphate (Pi) between cellular compartments. It has been discovered that mutations in this protein cause lethality because the cell becomes incapable of controlling the intracellular levels of Pi, this being toxic for the cell. PhoR is a histidine kinase/phosphatase. When the Pi level is considered to be a limiting factor, PhoR autophosphorylates at a histidine residue and then donates its phosphoryl group to PhoB. On the other hand, when the Pi level is high, this protein removes the phosphoryl group from phospho-PhoB. Finally, the Pst is a signal transduction protein that acts as a transporter capable of switching its conformation during the transport of PI.
Semen is the thick fluid that contains the sperm that is basic in nature, thus protecting it from the acidic nature of the vagina.
One example of irradiation solving a societal problem might be the way
in which it is able to prevent diseases in food. Using small amount of
radiation, the bacteria and insects that would otherwise be carrying
harmful bacteria can be killed. This will solve a societal problem, in
that food wastage and illness due to food poisoning in poverty-stricken
areas are massive problems faced in our society.