Week 2

Question 1

What are the types of intercellular communication (5)

Answer 1

Autocrine
Paracrine
Contact-mediated
Synaptic
Endocrine

Question 2

What is Kd

Answer 2

Binding affinity of a receptor
When binding saturation is 50%
(The lower the higher affinity, cause less dose is needed for action)

Question 3

What is Ec50

Answer 3

Characterizes potency of a drug
When bio response is 50%
Lower Ec50 is more potent
(Effective conc. 50)

Question 4

Biological response of Agonist, Partial Agonist, and Antagonist.

Answer 4

Agonist: 1 (100%)
P.Agonist: 0.5 (50%)
Antagonist: 0 (0%)

Question 5

Antagonists can be

Answer 5

Neutral Antagonists
Inverse Agonists

Question 6

Cariprazine

Answer 6

Stimulates / Inhibits D3/D2
Agonist / Antagonist
Works like dopamine but only 40-60%
Depression and Schizophrenia

Question 7

What are the Vasopressin Receptors

Answer 7

V1- Smooth Muscles
V2- Kidney

Question 8

Why do we administer Desmopressin if Antidiuretic Hormone is Low

Answer 8

Because administering Vasopressin directly would mean that both V1 and V2 receptors would be affected.
So smooth muscles and the kidneys would be affected.

Question 9

Desmopressin

Answer 9

V2 Receptor Agonist

Question 10

GPCR Steps

Answer 10

1) Agonist Binds R —-> R*
2) Receptor / G-protein Interaction a-GDP to a-GTP.
3) G-protein dissociates from Receptor.
4) a and by subunits dissociate.
5) Subunits interact with effectors.
6) Termination and subunits bind again.

Question 11

What converts GDP to GTP

Answer 11

GEF
Guanine exchange factor
e.g: Active G-prot coupled Receptor

Question 12

What inactivates GTP to GDP

Answer 12

GAP
GTPase Activating Protein

Question 13

What types of receptors are Adrenergic R

Answer 13

All G Protein coupled receptors

Question 14

Gs Proteins Examples

Answer 14

B - Adrenergic R
ACTH R
Glucagon R

Question 15

What does PDE do? What can inhibit it>

Answer 15

Metabolizes cAMP to AMP
Caffeine, leads to more alertness.

Question 16

G i/o Protein Examples

Answer 16

a2 - Adrenergic R
Opiate R
Cannabinoid R
Somatostatin R

Question 17

Effects of G i/o Proteins

Answer 17

Inhibition of Adenylyl Cyclase (no cAMP)
Activation of K Channels
Inhibition of Ca Channels
Phospholipase A2 Activation

Question 18

3 Paths of Arachidonic acid Signaling

Answer 18

Cyclooxygenase
Lipoxygenase
Epoxygenase

Question 19

What does Arachidonic acid in cyclooxygenase path produce?

Answer 19

Prostaglandins
Therefore, blocking COX helps with fever inflamation and pain.

Question 20

What Mediates Transducin and Gustducin actions?

Answer 20

cGMP —> GMP

Question 21

G q/11 Protein Examples

Answer 21

a1 R
Angiotensin R

Question 22

Events after Gq/11 activation

Answer 22

1) a subunit activates Phospholipase C.
2) PLC acts on PIP2
3) DAG+ IP3
4) DAG activates PKC
5) IP3 –> R –> Opens Ca flux from ER to cytoplasm.

Question 23

What does Capacitive Ca entry do?

Answer 23

Ensures that Ca stores in cell (ER) do not get depleted

Question 24

Capacitive Ca mechanism / SOC

Answer 24

STIM-1 Ca Sensor
Orai-1 Ca Channel

Question 25

What happens in response to increased Ca (Signal)

Answer 25

Ca binds Calmodulin, forms complx Ca-Calmodulin activate CAM Kinases CAMK phosphorylate target proteins

Question 26

Ga 12/13 Protein examples

Answer 26

Thrombin R Angiotensin R

Question 27

G 12/13 Protein mech

Answer 27

1) a 12/13 - GTP activates GEF (Rho) 2) Rho - GTP 3) Rho Kinases

Question 28

Actions of Gt (Transducin) and Gg (Gustducin) Protein

Answer 28

1) at/g - GTP Activate PDE 2) PDE metabolizes cGMP to GMP

Question 29

What is Desensitization

Answer 29

The deactivation of a G-protein coupled receptor

Question 30

2 Methods of desensitization

Answer 30

Agonist dissociation B-Arrestin Binding

Question 31

Types of Cholinergic receptors

Answer 31

Nicotinic / Ion channels Muscarinic / GPCRs

Question 32

Receptor Tyrosine Kinases Ligands

Answer 32

Growth Hormone Insulin

Question 33

Activation mech of Tyrosine Kinase receptors

Answer 33

1) Agonist Binding 2) Receptor dimerization 3) Autophosphorylation of Tyr

Question 34

RAS Pathway

Answer 34

1) Ligand binds to RTK 2) RTK autophosphorylation 3) SH2 binds phosphotyrosine 4) SOS binds (GEF) 5) RAS (GDP to GTP) 6) MAPK Phosphorylates cytosolic proteins and nucleus.

Question 35

What inhibits apoptosis and keeps cell survival

Answer 35

PI 3 Kinase

Question 36

What type of R is ANP-receptor

Answer 36

Guanylyl cyclase R

Question 37

Guanylyl Cyclase / ANP Receptor mech

Answer 37

1) ANP (Agonist) binds GC. 2) GC makes cGMP 3) PKg ----> Smooth m relaxation

Question 38

What is JAK

Answer 38

Tyrosine Kinase (Janus Faced Kinase)

Question 39

Cytokine receptor examples

Answer 39

Growth Hormone R Prolactin R

Question 40

JAK can phosphorylate

Answer 40

Receptors Other JAK STAT proteins

Question 41

What does phosphorylation of STAT proteins lead to?

Answer 41

This effects the nucleus Leads to up/down reg. of gene expression (Slow)

Question 42

What type of Agonists are used for Intracellular R

Answer 42

Lipid permeable agonists

Question 43

Types of Intracellular Receptors

Answer 43

Cytosol (Type-I) / Glucocorticoid R Nucleus (Type-II) / Thyroid HR R

Question 44

Can lipid permeable Agonists be used other than Intracellular receptors

Answer 44

Yes, in Plasma m. R (Faster) in Cannabinoid R and Prostaglandin R

Question 45

NO Signaling

Answer 45

1) NO made by NOS 2) NO binds Guanylyl Cyclase 3) GTP ---> cGMP (Leads to vasodilation)

Question 46

2 Examples of Gene regulation

Answer 46

cAMP JAK - STAT Pathway

Question 47

5 mechanisms of Intracellular Ca homeostasis

Answer 47

1) Gq 2) PLC 3) Voltage gated channel 4) Ligand-Gated channels 5) CICR 6) RYR (Ryanodine R)

Question 48

OFF mechanism of Ca signaling

Answer 48

1) SERCA (Sar/endo Ca ATPase) 2) PMCA (P.m. Ca ATPase) 3) NCX (Na/Ca exchanger)

Question 49

What activates the endocytosis of a GPCR

Answer 49

Arrestin Binding