At what point during protein synthesis are genes
expressed?

When the protein for a particular gene is formed, the gene is expressed

Explanation:

Gene expression is the process in which the information from a gene is used for the synthesis of protein. The gene code for protein and the protein regulate the function of the cell in the body.

into RNA by the help of enzyme RNA polymerase. The next step is the translation in which the messenger RNA is decoded in the ribosome to produce a specific amino acid or the polypeptide chain that perform a specific function in the cell.

i am going to guess that it is co2.