Hormone receptors

Question 1

List some water-soluble hormones

Answer 1

Norepinephrine
Insulin
Epinephrine
Dopamine
Serotonin
Glucagon
ADH

Question 2

Which hormone exclusively uses the adenyl cyclase pathway?

Answer 2

epinephrine

Question 3

Which hormones exclusively use the phospholipase C pathway?

Answer 3

ADH
oxytocin

Question 4

Which hormone exclusively uses the tyrosine kinase pathway

Answer 4

Insulin

Question 5

What is the function of ANP (atrial natriuretic peptide)

Answer 5

Relaxes smooth muscle cells
increased secretion of Na and water by kidneys
Vasodilation

Question 6

Describe the tyrosine kinase receptor using insulin as example

Answer 6

Insulin receptor = transmembrane protein with alpha and beta subunits
Insulin hormone binds to extracellular alpha subunit => conformational change in receptors => beta subunit undergoes phosphorylation creating a docking site for intracellular signalling molecule

Question 7

List some lipid-soluble hormones

Answer 7

testosterone
oestrogen
progesterone
cortisol
aldosterone
thyroxine
retinoic acid
Vit D

Question 8

How does cortisol affect the cell?

Answer 8

Passes through cell membrane and binds to glucocorticoid receptor
Cortisol-glucocorticoid complex => nucleus where it inhibits or enhances gene transcription

Question 9

What are response elements?

Answer 9

DNA sequences that serve as binding sites for specific transcription factors

Question 10

What are ras-oncogenes?

Answer 10

group of cells whose normal function is to regulate cell growth and differentiation
Can cause cancer when overactivated

Question 11

Which are faster, lipid soluble or water soluble hormones?

Answer 11

Water soluble:
- bind to cell surface and rapidly trigger signal transduction pathways involving secondary messengers (e.g., cAMP) which rapidly activate enzymes or ion channel to initiate a cascade of intracellular events
- signal is also amplified
- FASTER

Lipid soluble:
- regular gene expression => protein synthesis
- takes time