Ah, I see your point. I suspect that Swahili's "asidi deoxyribonucleic" is probably an English loan-word, but you're right that I don't know, since I haven't done any real research.
But even for scientific writing, my dictionary translates DNA as 脱氧核糖核酸, where 脱 means peel off, 氧 means oxygen, and 核糖核酸 means RNA, so DNA = de-oxy-RNA. As for RNA, 核糖 means ribose and 核酸 means nucleic acid. And in 核酸, 核 means nucleus/core/pip and 酸 means sour/acid, so again the meaning of the characters joined together are simply the sum of their parts. That's always been the case in my limited experience with medical words in Mandarin.