Question

Answer the following questions regarding the Endocrine System.

a) What trimeric (3 subunits) protein is membrane-bound and activated when epinephrine binds the Beta-2-adrenergic receptor?

b) What category of hormone can pass directly through the cell phospholipid bilayer to bind its receptor and directly regulate gene activity?

c) If serum T3 and T4 are low, the hypothalamus will secrete Thyrotropin Secreting hormone (TRH) to target what specific gland?

Will rate if answers are correct. Thanks

Answer 1

answer

A) trimeric protein is G protein contain G alpha beta gamma

epinephrine is catacholamine secreted from Adrenal medulla act through G protein couple receptor to Adenylyl cyclase enzyme which breatdown ATP to C-AMP( cyclic AMP) which act as seccondary messenger

B) Steroid hormones go directly through the cell lipid layer their receptor are present inside the cell in cytoplasm and nucleus

eg . thyroid hormone and vit D hormone , sex hormones

C) answer Thyroid gland ..

its feedback mechanism system

when body throid hormone level is low then

hypothalamus secretes Thyroid releasing hormones which act on ...>thyroid gland secretes ..T3 T4 hormones ...> level the T3 T4 to normal level

condition where T3 T4 low is called hypothyroidism