BIOL 1412 ENDOCRINE SYSTEM EXAM
QUESTIONS WITH 100% CORRECT
ANSWERS LATEST VERSION 2025/2026.
What does the endocrine system do? - ANS -Regulates growth, repro, metabolism (long-ter
events)
-glands and tissues secrete hormones which travel in the blood to target cells (= cells with
specific receptors for that hormone)
-bind to receptors and change cell activity
Where are the receptors (proteins) found: - ANS - on the cell membrane
- intracellular (nuclear)
What are the different types of hormones? - ANS 1) Water-soluble hormones
2)Lipid soluble membrane
What are water soluble hormones? - ANS -peptide proteins, catecholamines (=1st
messenger)
What are the steps of a water soluble hormones? - ANS 1) Hormone binds to cell membrane
receptors (does not enter cell for its action)
2) Hormone-receptor complex activates membrane proteins ex, G proteins
1 @COPYRIGHT 2025/2026 ALLRIGHTS RESERVED.
, 3) G protiens then activate= 2nd messengers ex; cAMP, Ca2+ = second messenger
What are some explains using cAMP (cylic adenosise monophosphate) as second messenger? -
ANS 1) Hormone binds to cell-surface receptor - activates G-protein(s)
2) g-protiens activates adenylate (adenylyl cyclase (membrane protein)
3) Adenylate cyclase converts ATP to cAMP (=second messenger) therefore increase [cAMP]
4) cAMP - activates protein kinases (in cytosol)
5)protein kinase acts on (phosphorylates) other proteins to alter their activity therefor changes
cell activity
ex; Epinephrine on liver cells (activates cAMP) - causes breakdown of glycogen to glucose -
released to blood
Why use 2nd messenger systems? - ANS a) hormone cant enter the cell (water soluble)
b) rapid-acting (enzymes already present - just activate)
c) 1 hormone molecule - many enzyme molecules activated - multiplies signal
Why is the 2nd messenger broken down or removed? - ANS to end cellular response
-cAMP broken down by phosphodiesterase in cell
What are lipid soluble hormones? - ANS -steroid (cortisol) and thyroid hormones
-trigger protein synthesis
-takes time therefor slow, but long-lasting response
2 @COPYRIGHT 2025/2026 ALLRIGHTS RESERVED.
QUESTIONS WITH 100% CORRECT
ANSWERS LATEST VERSION 2025/2026.
What does the endocrine system do? - ANS -Regulates growth, repro, metabolism (long-ter
events)
-glands and tissues secrete hormones which travel in the blood to target cells (= cells with
specific receptors for that hormone)
-bind to receptors and change cell activity
Where are the receptors (proteins) found: - ANS - on the cell membrane
- intracellular (nuclear)
What are the different types of hormones? - ANS 1) Water-soluble hormones
2)Lipid soluble membrane
What are water soluble hormones? - ANS -peptide proteins, catecholamines (=1st
messenger)
What are the steps of a water soluble hormones? - ANS 1) Hormone binds to cell membrane
receptors (does not enter cell for its action)
2) Hormone-receptor complex activates membrane proteins ex, G proteins
1 @COPYRIGHT 2025/2026 ALLRIGHTS RESERVED.
, 3) G protiens then activate= 2nd messengers ex; cAMP, Ca2+ = second messenger
What are some explains using cAMP (cylic adenosise monophosphate) as second messenger? -
ANS 1) Hormone binds to cell-surface receptor - activates G-protein(s)
2) g-protiens activates adenylate (adenylyl cyclase (membrane protein)
3) Adenylate cyclase converts ATP to cAMP (=second messenger) therefore increase [cAMP]
4) cAMP - activates protein kinases (in cytosol)
5)protein kinase acts on (phosphorylates) other proteins to alter their activity therefor changes
cell activity
ex; Epinephrine on liver cells (activates cAMP) - causes breakdown of glycogen to glucose -
released to blood
Why use 2nd messenger systems? - ANS a) hormone cant enter the cell (water soluble)
b) rapid-acting (enzymes already present - just activate)
c) 1 hormone molecule - many enzyme molecules activated - multiplies signal
Why is the 2nd messenger broken down or removed? - ANS to end cellular response
-cAMP broken down by phosphodiesterase in cell
What are lipid soluble hormones? - ANS -steroid (cortisol) and thyroid hormones
-trigger protein synthesis
-takes time therefor slow, but long-lasting response
2 @COPYRIGHT 2025/2026 ALLRIGHTS RESERVED.
