Second Messengers

Question 1

List 9 examples of second messengers

Answer 1

DAG, phosphatidylinosotol , IP3,Ca, cAMP,cGMP. NO,CO,H2S

Question 2

List the 3 Types of second messengers and give examples

Answer 2

hydrophobic molecules:membrane associated.DAG, phosphatidylinosotol.

• hydrophilic molecules:water soluble molecules located within the cytosol. IP3,Ca, cAMP,cGMP.
• Gases: NO,CO,H2S . Which can move thorough the cytosol and across cell membrane

Question 3

—— is converted to cAMP by ——- enzyme

Answer 3

ATP

active form of adenylcyclase

Question 4

As a regulation, cAMP can be converted to ——- by —— enzyme

Answer 4

AMP

phosphodiesterase

Question 5

Mention 3 cAMP TARGETS

Answer 5

PKA

EPACs

CREB

Question 6

Full menaning of pKa

Answer 6

Camp dependent protein kinase A

Question 7

Full meaning of EPAC

Answer 7

Camp regulated guanine nucleotide exchange factors called

Exchange protein directly activated by camp

Question 8

Full meaning of CREB

Answer 8

Camp response element binding protein

Question 9

Full meaning OF cAMP

Answer 9

cAMP = cyclic 3,5 Adenosine monophosphate

Question 10

——ion aids the conversion of ATP to cAMP

Answer 10

Mg

Question 11

Adenylate cyclase is activated by stimulatory G(—)-protein-coupled receptors

Answer 11

gs

Question 12

cAMP can be inhibited by cylase inhibitory G (—-)-protein-coupled receptors

Answer 12

Gi

Question 13

Effect of the following on cAMP.
PGE1 :\_\_ 
-Adenosine:\_\_\_\_ 
-ACTH:\_\_\_\_\_ 
-Glucagon:\_\_\_\_\_ 
-adrenaline:\_\_\_\_\_

Answer 13

inhibitory

inhibitory

excitatory

excitatory

excitatory

Question 14

adenylcyclase is——- kind of protein

Answer 14

an integral membrane protein

Question 15

the most common downstream effector of cAMP is——-

Answer 15

protein kinase A

Question 16

PKA is normally——- as a —-meric —-enzyme.

Answer 16

inactive

tetra

holo

Question 17

nature of PKA is from——- units and———- units

Answer 17

2 catalytic

2 regulatory

Question 18

the—— units always block the——- units of the PKA by binding to it———

Answer 18

regulatory

catalytic

non-covalently

Question 19

——camp molecules bind to each PKA——— subunit

Answer 19

2

regulatory

Question 20

active PKA——- CREB.

-CREB binds to a—— region and then binds to a——-(——-) which co-activates—— and allows it to——-

Answer 20

activates

CRE

CBP

creb binding protein

CREB

switch certain genes on and off to alter transcription

Question 21

CREB proteins in neurones are thought to be involved in the formation of——

Answer 21

long-term memory

Question 22

CREB is important for the survival of neurones . T/F

Answer 22

T

Question 23

cAMP mediates some ——aspects of synaptic transmission

Answer 23

short-term

Question 24

CAMP signaling cascade!
Step 1
-ligand binds to—— ; leads to——- in the receptor and exposing binding site for——
Then ——diffuses to come in contact with the—- to activate the—— for—— exchange

Answer 24

receptor

conformational changes

G protein

Gprotein

ligand-receptor complex

G protein

GTP-GDP

Question 25

CAMP signaling cascade!
Step 2
(a)——displaces—— leading to—- of Gprotein dissociating from it and exposing a binding site for—— on the——
-the subunit binds to and activates—— to produce molecules of——
(b)——of the GTP by the subunit returns it to its original configuration so it release adenylcyclase (making it——) and binding back to———
-activation of cyclase is repeated till———

Answer 25

GTP
GDP
alpha subunit
Adenyl cyclase
alpha subunit 
Adenyl cyclase
cAMP
hydrolysis
inactive
beta subunit
the Ligand dissociates from the receptor

Question 26

G protein-coupled receptor can’t interact sequentially with more than one G protein macromolecule.
T/F

Answer 26

F

Question 27

———complex can open multiple ion channels

Answer 27

beta-gamma

Question 28

Cytochrome C oxidase is an inhibitor of Nitric Oxide

T/F

Answer 28

T

Question 29

cAMP works on only PKA of the protein kinase series

T/F

Answer 29

F. Works on PKG too

Question 30

Adenyl cyclase contains —- transmembrane segments

Answer 30

12

Question 31

PKA can’t phosphorylate other protein kinases.

T/F

Answer 31

F