endocrine organisation Flashcards
What is the solubility of peptide hormones?
Water soluble
Why can peptide hormones be stored?
They are water soluble, so cannot pass through cell membranes unassisted
What is the function of peptide hormones?
Activate second messenger systems to alter protein activity
What is the relative speed of action of peptide and steroid hormones?
Peptide hormones act rapidly (minutes) while steroid hormones have a slow response (hours-days)
What is the solubility of steroid hormones?
Lipid soluble
Why can’t steroid hormones be stored (except thyroid precursors)?
They are lipid soluble so can pass through cell membranes and into the blood stream readily
How are steroid hormones transported in the blood?
Bound to carrier proteins
How are the steroid hormones synthesised?
On demand, from cholesterol
What type of receptors do steroid hormones bind to?
Intracellular receptors
What is the function of steroid hormones?
Activate gene transcription to synthesise new proteins
