Question

Why is D2O poisonous to drink?

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Answer 1

D2O is different enough from water that the chemical properties of it are enough to cause toxicity in cells. This is because it has different hydrogen bonding than normal water (slightly stronger). This results in a hampering of protein functionality since protein form and function is highly reliant on a normal water based solvent; any changes to the hydrogen bonding will cause loss of function.
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