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This is a follow up to this previous question:

In biosynthesis of cysteine and methionine, where does the sulfur come from?

Can animals use gaesous H2S in the atmosphere, say for instance from a sulfur rich hot springs, to aquire sulfur?

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No, they can not do this. We don't have the enzymes to metabolize H2S, besides that, it is highly toxic. H2S can be used by some bacteria and archea (so called lithotrophic bacteria), but they are relatively rare.

Sulfur is reduced by plants, which take it up in the form of sulfates and subsequently reduce it to form different sulphur compounds. Animals are dependent on the uptake of sulphur from plant sources, as the sulphur containing amino acids are essential (meaning the cannot be synthesized by themself). The pathway is relatively complex. The image below is from the Wikipedia article on Sulphur assimilation, which I can also recommend, if you want to know all the details.

enter image description here

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Geat reference, thanks so much. But one comment, I read somwhere that gaseous H2S in the atmosphere was highly correlated with reduced blood pressure. – Ahfoo Mar 13 '14 at 5:43

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