>>11903610sorry, not enzymes, i was confusing it with testosterone. similar problem though, it's competition for receptor binding sites.
imagine a lock and a key. the key fits perfectly in the lock. in this metaphor, the receptor that detects the presence of human estrogen is the lock, and human estrogen is the key.
now imagine you have another key that's ALMOST the right key. that's estrogen-like compounds from other species. you can stick it in the lock, cause it's almost the right shape, but to turn the key you have to spend a lot of time jiggling the key, and maybe apply some force. or maybe you can't even turn it at all, the key just gets stuck. and if you want to go back to the right key, the human estrogen, you have to take the key out, find the right key, and use it.
there's only one binding site on a receptor, and a poorly active estrogen is already bound, it doesnt matter if there's also human estrogen floating around.
