DNA is a huge molecule with lakhs of genes. At time of protein synthesis, only one or a few genes are needed which is very difficult to synthesize directly from that huge molecule.
Secondly, DNA is a very important molecule, which remains inside nucleus. All the protein synthesizing elements like amino acids etc are present in cytoplasm. So protein synthesis inside nucleus is impossible.
<h3><u>Explanation:</u></h3>
DNA is the genetic molecule of an organism. It is a huge polymer of different nucleotides stacked together one after the other. One gene occupies a very small fragment of this DNA. So during protein synthesis, if protein is directly synthesized from the whole DNA, a huge portion of energy will be lost fully unwinding the helical structure. And there will be more chances of an error and mutations will creep in very easily.
Secondly, DNA remains inside the nucleus of a cell. And inside the nucleus there's no entry of amino acids, which are essentially needed for protein synthesis. So protein synthesis from DNA is very risky and practically not feasible.
