Is cGMP not high in dark conditions?

In question code C3Y3K-7DHBJ which is, “all of the following are true regarding the photoreceptors except:” the correct answer is “cGMP is increased in the dark. Reading the explanation and the associated article gives me the opposite impression, that cGMP is indeed increased in the dark, instead of it being an untrue statement.

I’d love some feedback as to how I’m understanding is wrong, because I probably am. Pathways leave me very confused sometimes.

1 Like

This is the explanation, which I find a little difficult to follow fully tbh. Probably not because it’s written poorly but because it is so technical that I am unable to follow lol

1 Like

Hi, I am Sujata, author of Achievable USMLE. Sorry there was a typo in the options. cGMP does increase in the dark as it is not converted to 5’GMP. The enzyme that converts cGMP to 5’GMP is a phosphodiesterase which is activated by transducin. Hope that helps!


@Huge_tomato_silkworm, thanks for bringing this to our attention!

I’ve just updated the question to correct this typo.

If you see anything else that looks out of place, please let us know and we’ll investigate.

Perfect, and thanks for the quick response!

1 Like

No, thank you guys. I’m glad to pay a small amount in improving this amazing project. Also just saw my automatically generated username. Love it and will adopt it on my social media lol

1 Like