Naked Science Forum

Life Sciences => Cells, Microbes & Viruses => Topic started by: mikep on 23/10/2009 06:14:25

Title: How do we get nitrogenous bases into our body?
Post by: mikep on 23/10/2009 06:14:25

I know that DNA replicates itself when cells are created, but I was just wondering where the actual materials (nitrogenous bases, etc) that make up DNA come from. We can't just have the materials lying around waiting to be made into DNA, right?

Title: How do we get nitrogenous bases into our body?
Post by: Nizzle on 23/10/2009 09:38:17

People that eat will get the basic ingredients to synthesize these materials from their food
People that don't eat will die

Title: How do we get nitrogenous bases into our body?
Post by: chris on 24/10/2009 12:04:48

The building blocks of DNA are nucleotide bases - A, C, T and G. These are produced by metabolic pathways in cells to sustain an available pool of raw materials for a cell to use; production is increased or scaled back according to how well stocked the cell is.

This is rather like the stationery stockroom at the office where there are piles of pens and pads for workers to collect and use. The office secretary keeps an eye on how much "stock" is in the cupboard and orders more when supplies run low.

Chris

Title: How do we get nitrogenous bases into our body?
Post by: mikep on 24/10/2009 19:21:32

but where does the supply come from? is it traced back to our food?

Title: How do we get nitrogenous bases into our body?
Post by: chris on 24/10/2009 20:27:29

That's right. Everything your body needs must be eaten, drunk or breathed in, in one form or another. The raw materials for making organic bases are all in food; the body dismantles the constituents of every meal and re-deploys the resulting chemicals into biochemical pathways that make new molecules. That's how body-builders turn high-protein diets into muscle, a growing baby turns milk into an enlarging skeleton and a pregnant woman can grow a new human form from scratch.

Chris