Final answer:
Codons in mRNA molecules do not bind to complementary anticodons in tRNAs.
Step-by-step explanation:
One thing that is NOT true about codons in mRNA molecules is that codons in mRNAs bind to complementary anticodons in tRNAs. Codons in mRNA actually specify the sequence of amino acids in a protein, and they are read by the ribosome during translation. The anticodons in tRNA molecules are complementary to the codons and base pair with them, ensuring that the correct amino acid is added to the growing polypeptide chain.