Protein as Fuel in Cellular Respiration

I am little confused with the explanation but here is what I know about proteins:

When, glucose storage is used up, anterior pitutary relases ACTH, which increases the production of cortisol. Cortisol help break proteins in to amino acids, which are then deaminated in the cytoplasm (the by-product is NH3, which is converted to urea in liver). The deamination process is done by the peroxisomes. Now the deaminated a.a are then used in the metabolism (not sure but maybe they enter the cell metab. as acetyl coA).

Also, know that when insulin is present, it promotes the synthesis of proteins from a.a so they will not be used as fuel, rather it promotes the use of glucose, which will help get rid of glucose!

Speaking of protein metabolism, also know the fatty acid metabolism.

Hope this helps