hormones Flashcards
what is adrenaline
a hormone produced by the adrenal glands in times of stress that will prepare the body for emergency
what is the second messenger model
the way a non lipid soluble hormone acts on the cell, by triggering production of intermediary messengers
how does the activation of glycogenolysis occur with glucagon
- glucagon binds to liver cell membrane receptors
- G protein is activated which activates the enzyme adenylyl cyclase by changing its shape.
- active adenylyl cyclase converts ATP to cAMP
- cAMP is the secondary messenger which stimulates the protein kinase
- protein kinase enzyme activates a cascade which will catalyse the breakdown of glycogen to glucose
how is glycogenolysis stimulated with adrenaline
- adrenaline won’t bind to the same receptors as glucagon. but still does
- this causes adenylyl cyclase to change shape and become activated.
active adenylyl cyclase catalyses the conversion of ATP to cAMP which is the second messenger. - cAMP will stimulate protein kinases
- ## protein kinase enzymes activate a cascade which catalyses the breakdown of glycogen to glucose
what does adrenaline inhibit
glycogenesis
what are four other actions of adrenaline to increase blood glucose
- stimulates the breakdown of glycogen stores in muscles during exercise
- activates glucagon and inhibits insulin
- ## secreted in low blood glucose concentrations
what is the function of ADH
if a low water potential is detected more of this hormone is released. it makes the walls of the DCT and collecting duct more permeable to water meaning less water will leave via excretion
how does adh actually work - what is the mechanism
- ADH binds to the receptors and causes a chain reaction of enzyme controlled reactions inside the cell- using the second messsenger model.
the cascade causes the the vesicles containg the aquaporins to move and fuse with the membrane - this makes the membrane of cells lining the collect duct more permeable to water
where is ADH released from
pituitary gland
what is diabetes mellitus
a condition where blood glucose concentration cannot be controlled properly
whta is type 1 diabetes
where the body doesnt produce enough insulin
what is type 2 diabetes
where the body does not respond to insulin
what is hyperglycaemia
where blood sugar levels are super high
what is hypoglycaemia
where blood sugar levels are too low after too much insulin