GMS 6552 EXAM 1 ACTUAL TEST PAPER QUESTIONS AND CORRECT ANSWERS COMPLETE SOLUTION GUIDE

GMS 6552 EXAM 1 ACTUAL TEST PAPER
QUESTIONS AND CORRECT ANSWERS
COMPLETE SOLUTION GUIDE

●● Channel-Linked (Ionotropic) Receptors
Answer: Produce cellular effects in milliseconds
Nicotinic ACh receptor


●● GPCRs
Answer: Effects happen in seconds
Muscarinic ACh receptor


●● Kinase-linked receptors
Answer: Effects happen in minutes
Insulin receptor


●● Receptors linked to gene transcription
Answer: Effects happen in hours
Estrogen receptor


●● Heterotrimeric G proteins

,Answer: alpha, beta and gamma subunits


●● GPCR Components
Answer: More than 800 receptors
7 transmembrane domains
N and C termini
Conformationally flexible
Constitutively active


●● GPCR Ligands
Answer: Hormones, neurotransmitters, chemokine, ions, amino acids,
peptides


●● G-proteins
Answer: a-20
Gas- increases AC
Gai - decreases AC
Gaq - increases PLC
b(6)y(12)


●● Why use G proteins
Answer: Means of amplifying the signal

, G proteins can regulate more than one effector


●● PKA
Answer: Phosphorylase Kinase (glycogen breakdown)
CREB (gene transcription)
L-type Ca channels (heart contraction)
Pyruvate Kinase (glycolysis)
Hormone Sensitive Lipase (triglyceride breakdown)


●● Kinase-linked receptor signaling
Answer: No second messenger


●● Protein kinase-linked receptors
Answer: Receptors associated with cytosolic kinases
Receptor tyrosine kinases
Receptor serine/threonine kinases


●● Receptors associated with cytosolic kinases
Answer: Ligands:
Prolactin
GH
Interferons