Following oral sex, what happens to the sperm, or specifically the DNA, when it’s swallowed? Does it break down in the stomach, and what exactly does it become? And do these substances get utilized by the body, or passed through and expelled in the urine or feces?
So, for how long after the “event” does my DNA actually exist in my partner’s body?
DNA is just made out of amino acids. And every other meat you eat (as 'twere) is made of cells, which have nuclei, which contain DNA. Sperm’s not exceptional in that respect. I imagine it’s as digestible as any other uncooked meat, and the more so since it’s already being served up at the unicellular level.
DNA is made out of nucleotides (a pentose sugar ring, a phosphate and a nitrogenous base), whereas amino acids joined together would make a protein.
Chromosomes are made from one DNA molecule and histone proteins, they’re bonded by the negatively charged phophate groups on the nucleotides and the positive z-groups of the amino acids.
Everything you eat contains DNA, with the exception of salt and water. It gets broken down to the level of nucleotides or beyond, IIRC, which get absorbed and used in your own body in some way. Nucleotides can get broken down and atoms shuffled around into other molecules in a huge metabolic web.
I think it’s likely that once the DNA in whatever you ingest gets broken down to the building block level, it will get used to rewrite your own genome for/in whatever cells are still being replenished by cell division.
Which is an oddly impressive thought for me, for some reason.
Apart from salt, which you’ve already mentioned, there are lots of food additives and flavourings which are synthesized or which are obtained from inorganic sources. But I can’t think of anything apart from water which we ingest in large quantities and which doesn’t come from something with DNA.
Both salt and water have been cycled fast enough and for long enough that any salt or water you may consume also came from something with DNA. The mayterial may have been liberated and filtered since then, but the same is true dairy products, sugar and a whole slew of other foods.