A question from ds1: why is wee yellow?

[Dottydot]

I know I should know but I dozed through most of biology and ds1 (5) was saying at tea time that he's very interested in wees ()(if only we could persuade him to start doing them standing up...) and why are they yellow?

Dp (the one with brains) is at work so I said I didn't know but I'd put it into the computer and someone would tell me.

Over to you...

Was interested enough to google it - plus I know ds will ask me soon enought.
The yellow color in urine is due to chemicals called urobilins. These are the breakdown products of the bile pigment bilirubin. Bilirubin is itself a breakdown product of the heme part of hemoglobin from worn-out red blood cells. Most bilirubin is partly broken down in the liver, stored in the gall bladder, broken down some more in the intestines, and excreted in the feces (its metabolites are what make feces brown), but some remains in the bloodstream to be extracted by the kidneys where, converted to urobilins, it gives urine that familiar yellow tint.

If you eat lots of beetroot it's red

Right - thanks - I'll just go off and explain to ds1, who will probably remember every word and can impress his teachers next week!

Really?! It's almost worth trying that..!

ie your liver and kidneys clean up your blood to keep it nice and fresh, the yellow colour is one of the colours of old worn-out blood, and comes out in your week. Brown is another colour that comes from the old worn out blood and that makes your poo brown. (I think!)

And if you eat asparagus it smells funny.

The wee, not the sparragrass.

Remember, don't eat the yellow snow

my wee is bright green thanks to my multi vitamin - it's amazing!!!!!