“Is molecular binding of hormones HY on USMLE?”

Ajouté : 2026-05-19

[00:00:00]Is the molecular binding of hormones high yield for your Step 1? Absolutely.

[00:00:04]And I've made reels and YouTube clips on this stuff before.

[00:00:08]I'll tell you exactly what you need to know without the garbage, okay? Just the clean points for your Step 1, okay? So, this is what's going to go down.

[00:00:17]You need to know that steroid hormones progesterone, estrogen, testosterone, cortisol, aldosterone all these steroid hormones they bind to intracellular receptors.

[00:00:31]Where in turn going to get translocation to the nucleus where we're going to get upregulation of gene transcription.

[00:00:36]Is there more detail? The answer is yes.

[00:00:38]Are there alternative binding pathways?

[00:00:40]The answer is yes.

[00:00:42]But that's the answer you need to know for your Step 1. Steroid hormones bind to intracellular receptors.

[00:00:48]They translocate to the nucleus. We have upregulation of gene transcription. So far, so good?

[00:00:53]Okay. Now, one small nuanced additional detail is that estrogen can have a greater fraction that binds directly to nuclear receptors rather than intracellular receptors. So, estrogen can be considered the odd one out.

[00:01:10]So far, so good? Okay. Now, I also want you to memorize the next point is that vitamin D and vitamin A and thyroid hormones, T3, T4, they bind straight up to nuclear receptors.

[00:01:27]Okay? Not a big deal. High yield.

[00:01:30]Now, finally all other hormones for your Step 1 are going to bind to membrane receptors, okay? Plasma membrane-bound receptors. Now, this is what's going to happen on your Step 1.

[00:01:44]I'll tell you exactly what they're going to do.

[00:01:46]They're going to say there's some researcher who's uh evaluating hormone binding and determines that there is hormone X that binds to a plasma membrane receptor and they list a bunch of hormones and you're like, I have no [ __ ] idea. But then you'll simply see that let's say the answer is prolactin where the other answers are all steroid hormones. You just say, well, I don't know about the binding of the hormones necessarily, but I can clearly see that four of the answers are steroid hormones, whereas prolactin or growth hormone or LH or FSH hormones that are not steroid hormones or are not vitamin A, D, T3, T4, so all the other ones they are going to bind to plasma membrane receptors. Do you understand?

[00:02:39]So peptide hormones bind to plasma membrane receptors, steroid hormones intracellular receptors, estrogen combine to nuclear receptors.

[00:02:49]And then vitamin D, vitamin A, T3, T4, nuclear receptors. Do you get what I'm saying?