APEX-ANS EXAM QUESTIONS WITH
100% CORRECT ANSWERS 2026
VERIFIED A+
◉ what does agonism of Beta 2 receptors do?
Answer: Vasodilate in myocardium and skeletal muscle
Bronchodilate in lungs
◉ What are the three types of membrane bound receptors?
Answer: Ion channel, G-Protein Coupled receptor, and enzyme linked
receptor
◉ Example of enzyme linked receptor?
Answer: Insulin receptor in skeletal muscle it is linked to tyrosine kinase
◉ Example of G-protein coupled receptor
Answer: Alpha-1 receptor in vascular smooth muscle
◉ When an enzyme linked receptor has signal bind to it, what happens?
Answer: the analytic domain becomes activated since the receptor is also
an enzyme
◉ What binds to intracellular receptors and why?
,Answer: Steroids since they can diffuse through a cell membrane being
lipophillic Thyroid hormone bind to receptors in nucleus
◉ What are first messengers?
Answer: Extracellular chemicals such as NTs, hormones, drugs that
stimulates receptor. It is a ligand
◉ Describe the big picture of how G-Couples protein receptors work:
Answer: First messenger -> G-Protein couples receptor-> effector ->
second messenger->cellular response
◉ Where does the G-protein lay and what does it consist of?
Answer: inside the the cell membrane attached to receptor and consists
of 3 subunits, Alpha, Beta, and Gamma
◉ What G proteins are stimulatory proteins?
Answer: Gs and Gq
◉ What G proteins are inhibitory proteins?
Answer: Gi
◉ What happens when al ligand binds to a G-protein couples receptor?
Answer: The connection activates the G protein making it dissociate
from the beta and Gamma subunits and go to the effector, either turning
,on or turning off the effector. When the ligand unbinds from the receptor
the G protein Alpha subunit rejoins the beta and gamma units.
◉ What is the job of the effector?
Answer: Activate the second messenger
◉ What does a second messenger system allow for in single
transduction?
Answer: amplification
◉ What do second messengers modulate?
Answer: Network of enzymatic activity including phophotases and
protein kinases, intracellular response to second messenger is tissue
specific
◉ What are the 5 second messengers to know?
Answer: Cyclic Adenosine monophosphate (cAMP)
Cyclic guanosine monophosphate (cGMP)
Inositol triphosphate (IP3)
Diacylglycerol (DAG)
Calcium ion (Ca+2)
◉ What receptors increase phospholipase C?
Answer: Alpha 1, Muscarinic 1,3,5, Vasopressin 1, and histamine 1
, ◉ What does increased phospholipase C do?
Answer: increase second messengers IP3, DAG, and Ca+2
◉ What receptors are connected to G-protein Gq and what is their
effector?
Answer: Gq and phospholipase C
◉ What receptors are linked to a Gi protein?
Answer: Alpha 2, Muscarinic 2 and 4, Dopamine 2
◉ What is the effector for Gi protein?
Answer: Adenylate cyclase
◉ What does Gi proteins do to adenylate cyclase?
Answer: inhibit adenylate cyclase
◉ What does inhibited effector adenylate cyclase do?
Answer: Decreases cAMP production
◉ What receptors are linked to Gs protein?
Answer: Beta 1 and 2, Dopamine 1, Vasopressin 2, histamine 2
100% CORRECT ANSWERS 2026
VERIFIED A+
◉ what does agonism of Beta 2 receptors do?
Answer: Vasodilate in myocardium and skeletal muscle
Bronchodilate in lungs
◉ What are the three types of membrane bound receptors?
Answer: Ion channel, G-Protein Coupled receptor, and enzyme linked
receptor
◉ Example of enzyme linked receptor?
Answer: Insulin receptor in skeletal muscle it is linked to tyrosine kinase
◉ Example of G-protein coupled receptor
Answer: Alpha-1 receptor in vascular smooth muscle
◉ When an enzyme linked receptor has signal bind to it, what happens?
Answer: the analytic domain becomes activated since the receptor is also
an enzyme
◉ What binds to intracellular receptors and why?
,Answer: Steroids since they can diffuse through a cell membrane being
lipophillic Thyroid hormone bind to receptors in nucleus
◉ What are first messengers?
Answer: Extracellular chemicals such as NTs, hormones, drugs that
stimulates receptor. It is a ligand
◉ Describe the big picture of how G-Couples protein receptors work:
Answer: First messenger -> G-Protein couples receptor-> effector ->
second messenger->cellular response
◉ Where does the G-protein lay and what does it consist of?
Answer: inside the the cell membrane attached to receptor and consists
of 3 subunits, Alpha, Beta, and Gamma
◉ What G proteins are stimulatory proteins?
Answer: Gs and Gq
◉ What G proteins are inhibitory proteins?
Answer: Gi
◉ What happens when al ligand binds to a G-protein couples receptor?
Answer: The connection activates the G protein making it dissociate
from the beta and Gamma subunits and go to the effector, either turning
,on or turning off the effector. When the ligand unbinds from the receptor
the G protein Alpha subunit rejoins the beta and gamma units.
◉ What is the job of the effector?
Answer: Activate the second messenger
◉ What does a second messenger system allow for in single
transduction?
Answer: amplification
◉ What do second messengers modulate?
Answer: Network of enzymatic activity including phophotases and
protein kinases, intracellular response to second messenger is tissue
specific
◉ What are the 5 second messengers to know?
Answer: Cyclic Adenosine monophosphate (cAMP)
Cyclic guanosine monophosphate (cGMP)
Inositol triphosphate (IP3)
Diacylglycerol (DAG)
Calcium ion (Ca+2)
◉ What receptors increase phospholipase C?
Answer: Alpha 1, Muscarinic 1,3,5, Vasopressin 1, and histamine 1
, ◉ What does increased phospholipase C do?
Answer: increase second messengers IP3, DAG, and Ca+2
◉ What receptors are connected to G-protein Gq and what is their
effector?
Answer: Gq and phospholipase C
◉ What receptors are linked to a Gi protein?
Answer: Alpha 2, Muscarinic 2 and 4, Dopamine 2
◉ What is the effector for Gi protein?
Answer: Adenylate cyclase
◉ What does Gi proteins do to adenylate cyclase?
Answer: inhibit adenylate cyclase
◉ What does inhibited effector adenylate cyclase do?
Answer: Decreases cAMP production
◉ What receptors are linked to Gs protein?
Answer: Beta 1 and 2, Dopamine 1, Vasopressin 2, histamine 2
