Nice presentation, I have question about the degradation of glycogen using phosphoric acid. could you please explain if phosphoric acid can degrade glycogen.
It would be nice to explain the consequences of the processes. Like glycogen sythesis is important because... Its role is... In healthy individuals it is... in diabetic/obese/pre-diabetic individuals...
PKA and GSK work in tandem to down-regulate glycogenesis. cAMP (so intense energy usage) temporarily downregulates glycogen synthase by phosphorylating it via PKA into the inactive form. cAMP and large uses of ATP (so exercise) also tend to increase GSK3. In essence, both of these enzymes work together and are released from similar processes/environments: neither "deactivates" the other, both are involved in phosphorylating active glycogen synthase, and both appear to be released from similar processes (i.e increases in cAMP, increases in epinephrine, and massive ATP/ADP usage, of which, in this case, we would connect to increases in cAMP [weightlifting exercise/intense, laborious work/running]). However, during breaks in exercise or intense energy usage (even short ones), the inactive glycogen synthase is then dephosphorylated from the presence of large amounts of glucose that are in the cells/blood (assuming a carbohydrate rich meal was consumed before exercise). This process is a feedback loop that keeps the glycogen topped off from blood sugar/circulating glucose during exercise, and therefor, this stresses the importance of having some type of glucose pre-workout for most individuals, and also shows the elegant system and feedback loop of glycogen synthase in our bodies for keeping our muscles topped off, either from dietary carbs, or from glucagon released by the liver in response to low blood sugar. Another thing that is important to note is that the amount blood plasma glucose contributes to intense exercise increases in proportion as an energy substrate as glycogen is depleted - so even if glycogen is low or intense exercise tends to inhibit glycogen reuptake, it is still stresses the vital importance of having carbs preworkout/pre-work, especially if a person is lean and/or not sedentary: to provide a blood-based, non-liver generated energy source, to provide circulating carbohydrate substrates that can be stored as glycogen during breaks in intense labor/lifting, and to make sure muscle is spared from being used in gluconeogenesis because of the presence of bioavailable carbohydrate-based energy from blood glucose when glycogen is temporarily depleted.
Insulin suppresses GSK3, laborious activity increases both PKA and GSK3 through increases of cAMP via mass usage of ATP, but the presence of insulin decreases both enzymes... so during work-out/working, it is a feedback loop of downregulating glycogen synthase, with the presence of carbs/insulin upregulating active glycogen synthase/dephosphorylating the inactive form of phosphorylated glycogen synthase B.
