Hormones Solubility

Practice Question Solving
1

Hi everyone, there is a lot of conflicting evidence and information online so I just wanted to clear this up.
Lipid soluble hormones (steroids) can pass through the plasma membrane just by diffusion or do they need to bind to something beforehand?
Water soluble hormones can just pass through the membrane or do they need to bind to receptors on the cell membrane (I read that protein/polypeptides need to anyway, so do they need to do that?)
Also tyrosine derivatives (thyroxine, catecholamines) are the same as amino acid derivatives - soluble in water?
Cortisol is water soluble so does it pass through the membrane or bind to receptors?

Thank you guys in advance!! @AriHoresh

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2

For the IMAT, steroids pass easily and bond to a nuclear receptor, while proteins/water soluble use a receptor on the membrane.
The tyrosine, catecholamines, etc are a bit too advanced for the IMAT, so no worries.

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3

Thank you for the clarification Ari! Is cortisol the exception to steroid hormones since it has the hydroxyl group I assume it’s water soluble so it uses a receptor on the membrane?

4

Cortisol can also cross the membrane quite easily

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