Answer:
In the process of protein catabolism, the dissociation of proteins into amino acids and simple derivative compounds takes place. The produced amino acids then go through amino acid catabolism to get transformed into other compounds, which can enter Kreb's cycle.
In the process of protein catabolism, the proteins get converted into amino acids with the help of proteasomes, the process known as proteolysis. These amino acids further get cleaved individually by proteases.
In amino acid degradation, the dissociation of amino acids takes place, which further get transformed into sugars or glucose, the process is known as oxidative deamination. In the process, first the amino group of the amino acid gets withdrawn, then the remaining part of the amino acid becomes oxidized leading to the formation of α-keto acid.
The α-keto acid then moves into the Kreb's cycle in order to generate energy. The acid can also move into the process of glycolysis to generate pyruvate. After that, the conversion of pyruvate into acetyl-CoA takes place, which moves into the TCA cycle and transform the original molecules of pyruvate into ATP or functional form of energy.