rohudc

Oh okay! I can't thank you enough for your help! That question was bothering me for quite some time and many people to whom I asked had no clue.

Pyruvate will enter gluconeogenesis and give us the required glucose during fasting. Isn't it? So yup, now I get it, there clearly is a net gain in using amino acids as a fuel.

Yup, ALT stands for alanine aminotransferase. Omg, so glutamate dehydrogenase would act on the glutamate produced and give us alpha-ketoglutarate (eventually glucose) and NH3 enters the urea cycle. Am I right?

ALT converts alanine to pyruvate using α-ketoglutarate. How is this reaction useful when α-ketoglutarate will anyway be converted to pyruvate? This is solely in the context of producing glucose from glucogenic amino acids. When amino acids are the only option, the body uses them but if they are going to need TCA cycle intermediates to produce other TCA cycle intermediates/pyruvate, I don’t see any net gain.