Hormones Flashcards
What is a hormone
A substance that controls and regulates BIOLOGICAL FUNCTIONS by binding to a SPECIFIC RECEPTOR on cell surface/within target cell, triggerine a BIOLOGICAL EFFECT
What does autocrine mean
Local cell diffusion, acting on neighboring cells of the same type
what does Paracrine mean
Local cell tissue diffusion acting on different cells in the same tissue
What does endocrine mean
Distributed by blood, acting on distant target cells
What are the 3 types of hormone transport
Autocrine, paracrine, endocrine
What kind of hormone is insulin
A peptide hormone
How does pro-insulin become insulin
Pro insulin A and B chains are at opposite ends of the proinsulin chain, are cleaved from this, and they bind to each other
What amino acid is thyroxine derived from
Tyrosine
What amino acid is serotonin derived from?
Trytrophan
What are testosterone and calciferol both derived from, and what kind of hormones are they
cholesterol,
Steroid hormones
What are PGE2 and Leukotriene e4 derived from, and what kind of hormone are they
Arachidonic acid,
Lipid hormones
How do hormones such as Seretonin or GABA work to cause an effect
They target specific receptors, and when bound to it, allows it to act as an ion channel, allowing membrane depolarisation
How do G-protein receptors work
receptor is bound to a G protein made of alpha, beta and gamma subunits. When hormone binds to receptor this changes do GDP nbound to alpha is lost, and GTP binds.
When GTP binds, alpha become dissociated from the rest, binding to another thing. Can be Calcium channel for adrenaline,
Alpha dissociates back to aGDP and binds again
What happens when insulin binds to itc receptor
Phosphorylation of specific proteins using atp forming ADP
How do glucocorticoid hormones work
hormone crosses membrane, binds with hormone in the cytoplasm, moves to nucleus where it influences DNA for a response
