Endocrine System: Mechanism of Hormone Action: Second Messenger System
1. Water-soluble proteins such as PEPTIDES and CATECHOLAMINES bind to receptors located where on
the cell? ON THE CELL MEMBRANE
2. G proteins:
a. What is bound to the G protein in the inactive state? GDP
In the active state? GTP
b. What catalyzes the conversion of ATP to cAMP? ADENVLATE CYCLASE
c. What is known as the first messenger? HORMONES Second messenger? cAMP
d. A molecule of cAMP activates PROTEIN KINASE A, which can phosphorylate many proteins.
e. What is the enzyme that inactivates cAMP? PHOSPODIESTERASE
f. A single molecule of a hormone can have a large effect on the cell due to this process, called
AMPLIFICATION.
3. Insulin travels in the blood and binds to what type of receptors on the cell membrane? TYROSINE
KINASE
1. Water-soluble proteins such as PEPTIDES and CATECHOLAMINES bind to receptors located where on
the cell? ON THE CELL MEMBRANE
2. G proteins:
a. What is bound to the G protein in the inactive state? GDP
In the active state? GTP
b. What catalyzes the conversion of ATP to cAMP? ADENVLATE CYCLASE
c. What is known as the first messenger? HORMONES Second messenger? cAMP
d. A molecule of cAMP activates PROTEIN KINASE A, which can phosphorylate many proteins.
e. What is the enzyme that inactivates cAMP? PHOSPODIESTERASE
f. A single molecule of a hormone can have a large effect on the cell due to this process, called
AMPLIFICATION.
3. Insulin travels in the blood and binds to what type of receptors on the cell membrane? TYROSINE
KINASE
