What happens immediately after a pyruvate is brought into the mitochondria ?

Immediately after pyruvate is brought into the mitochondrion it is transformed into Acetyl-CoA. Acetyl-CoA is necessary for the Krebs cycle to begin, and the Krebs cycle is the next step of cellular respiration. Without pyruvate's transformation, glucose cannot continue the process and be converted into ATP. BOOM i'm awesome

a polymer is a chainlike molecule made up of small molecular units. these small molecular units are called monomers. monomers of polymer can be joined together either naturally or synthetically.  

sodium i think the chemical element of atomic number 11, a soft silver-white reactive metal of the alkali metal group.