Thread: DNA replication

So codons code for amino acids. But during new DNA replication, there are already proteins (enzymes) made of amino acids that sequentially come together to make new DNA. Where do all those enzymes come from (helicase, polymerases, ligases, topoisomerase) in the first place? In order for DNA to occur those enzymes need to be in place first right? Also where does DNA polymerase get its nucleotides to be inserted into the 3' strand? I am a 3' lagging strand.

Thanks.

What you're essentially talking about is one of the most fundamental areas of biology, namely cell theory. All cells are derived from pre-existing cells. The zygote contains all the enzymes necessary, as does its daughter cells etc. All new cells have the tools necessary for basic function. The only time this chicken and egg problem becomes a problem that requires more thought is at the origins of life.

Nucleotides are obtained in the diet or through biochemical pathways inside the cell - nucleotide metabolism is a very important area of cell biochemistry.