After the adenylyl cyclase reaction (which convert ATP into cyclic adenosine monophosphate-cAMP), cAMP level is directly increased. Next steps of PKA activation include:
• cAMP binding to regulatory subunits of PKA, as a result conformational change in the regulatory subunits of PKA is induced,
• catalytic subunits are detached and unleashed by regulatory subunits and as a result activated.
No, but it is known that old/sick prey is much easier to catch. The evidence is that, say, there's no old and sick prey. The predator has to eat regardless, and whatever is there for it to take, it will. Think of a lion and a zebra, and the zebra is eating grass in the middle of a field. The lion is going to take that chance.
384400km/.001m
= 384400000 pennies