Final answer:
When TSC is phosphorylated by AMPK, mTOR is inhibited, which leads to a decrease in cellular growth and protein synthesis as a part of the body's energy conservation mechanism.
Step-by-step explanation:
When TSC is phosphorylated by AMPK, the mTOR pathway is affected. Specifically, AMP-activated protein kinase (AMPK) phosphorylation of TSC2 is an important regulatory step. TSC, or tuberous sclerosis complex, is a key upstream inhibitor of the mammalian target of rapamycin (mTOR).
Therefore, the phosphorylation of TSC by AMPK leads to the inhibition of mTOR. This action is part of a cellular energy-sensing pathway where AMPK acts as an energy sensor. When cellular energy levels are low, AMPK is activated and it phosphorylates TSC2, which, in turn, activates the TSC complex to inhibit mTOR, leading to a decrease in cellular growth and protein synthesis processes that are energy-consuming.