Fat, sugars and proteins after digested to their monomers are converted to which molecule when they enter tca (krebs) cycle?

Acetyl CoA

Explanation:

Fat, sugars and proteins are digested into their monomers namely fatty acid and glycerol, simple sugar and amino acids respectively. These simple chemicals are finally digested into acetyl CoA.

Acetyl CoA enters the TCA cycle and is completely broken down into CO2 and H2O.  The energy released during redox reactions of the TCA cycle is stored in the form of NADH and FADH2 which then enter the oxidative phosphorylation.

that is wrong, its not thymus.