In a university class in scientific English, several students in their essays used the phrase "living bodies"—clearly a translation of 生体—to refer to the places where certain chemical reactions take place. The phrase sounded strange to me in the context, but I couldn't think of anything better, and all the English-Japanese dictionaries I checked translated 生体 as "living body" or "organism."
Then I noticed an article in Nature about a particular type of catalysis that, it says, takes place in "living systems." This strikes me as a better translation of 生体 for such very general scientific contexts.
(January 8, 2003)