The organic compounds that are the starting materials for compounds like fats and amino acids are called

The answer is; acetyl-CoA

This organic compound is an intermediate of the TCA/Citric/Krebs cycle. To make fats, the coenzyme is carboxylated to manolyCoA. This becomes a precursor fo palmitate and other lipids in the body by the addition of more manolyCoA.

The coenzyme is also a precursor to the formation of alpha-ketoglutarate, another intermediate of the TCA cycle, which is also a precursor in the formation of proteins.