Cell Signaling 1

Question 1

What hormone is present when you are dehydrated?

Answer 1

ADH

Question 2

What hormone is present when you have excess fluid/edema?

Answer 2

ANP/ANF

Question 3

What is the difference b/n Paracrine and Autocrine?

Answer 3

-Paracrine hormones act as signals to other cells, while autocrine hormones act as signals to the cell that produced it

Question 4

How many ligand molecules must bind a channel to open it?

Answer 4

2

Question 5

What is the advantage of a set up where you require simultaneous binding of two signals for a channel to open?

Answer 5

1. Low concentration of signal = channels are closed 2. Small change in signal =on state

Question 6

What do Benzodiasepines do?

Answer 6

Open chloride channels, hyperpolarizing neurons, brain less active

Question 7

What does Sulfonylurea do?

Answer 7

Blocks K+ channels to release more insulin in diabetes treatment

Question 8

How does lidocaine work?

Answer 8

-Temporarily blocks V-Na channels

Question 9

What does Nifedipine do?

Answer 9

-Blocks Calcium channels, dilating blood vessels to treat hypertension

Question 10

What are 5 common 2nd messengers?

Answer 10

1. cAMP 2. cGMP 3. Ca2+ 4. Inositol triphosphate 5. Diacyl Glycerol (DAG)

Question 11

What does the Gs receptor do?

Answer 11

Increases cAMP levels

Question 12

What does the Gi receptor do?

Answer 12

Inhibits cAMP production

Question 13

What does the Gq receptor do?

Answer 13

Increase Ca2+ levels

Question 14

What amino acids are usually targeted for phosphorylation in signaling pathways?

Answer 14

-Sering -Threonine -Tyrosine

Question 15

When is a G Protein in its active state?

Answer 15

When GTP is bound to the alpha subunit?

Question 16

What type of G Protein does Acetylcholine activate in the heart?

Answer 16

Gi

Question 17

What type of G Protein does Epinephrine activate in the heart?

Answer 17

Gs

Question 18

What smooth muscle receptor must be present for epinephrine to dilate a blood vessel? What G protein is used?

Answer 18

Beta-2 Gs

Question 19

What smooth muscle receptor must be present for epinephrine to constricta blood vessel? What G protein is used?

Answer 19

-allpha-1 -Gq

Question 20

Beta2 agonists like albuterol are bronchodilators. Albuterol binds to beta 2 receptors on the smooth muscle in the lungs and results in dilation of the airway. In this signaling pathway, formatio nof cyclic AMP from ATP is Enzymatic or Stoichiometric?

Answer 20

Enzymatic

Question 21

What converts cAMP back to AMP?

Answer 21

cAMP phosphodiesterase

Question 22

How is IP3 deactivated?

Answer 22

-Phosphorylated -Dephosphorylated -Ca2+ pumped out of cytosol

Question 23

How are activated G proteins inactivated?

Answer 23

Hydrolysis by intrinsic GTPase.

Question 24

How is epinephrine/catecholamines inactivated?

Answer 24

-Methylation by COMT and oxidation by MAO

Question 25

What causes Beta cells of the pancreas to release insulin?

Answer 25

-increase in blood glucose -increase in cytoplasmic ATP -K+ channels close -Ca2+ channels open -Membrane depolarizes -Vesicular release of insulin

Question 26

Signaling by insulin occurs primarily via: A. Ion Channels B. G-Protein Coupled receptors C. Altering Gene Expression D. Enzyme-linked receptor

Answer 26

D. Enzyme linked receptor

Question 27

Insulin Receptor is a: A. Tyrosine phosphatase B. Sering/threonin Kinase C. Tyrosine Kinase D. Lysine Acetylase E. Tyrptophan Phosphatase

Answer 27

C. Tyrosine Kinase

Question 28

The Function of IRS (Insulin Receptor Substrate) is: A. Function as a phosphatase B. Functions as a downstream kinase C. Acts as a glucose transporter D. Act as a docking site for other proteins/kinases E. Bind to and inactivate Insulin receptor

Answer 28

D. Act as a docking site for other proteins/kinases

Question 29

How do steroids act as signalling molecules?

Answer 29

They alter gene expression

Question 30

Synthesis of which of the following increases during inflammation? A. NFkB (nuclear factor kappa B) B. TNF-alpha C. IL-1 D. IL-2 E. All of the above

Answer 30

E. All of the above

Question 31

Which drug would you choose to treat a six year-old child with acute asthma attach? A. Albuterol B. Prednisone

Answer 31

A. Albuterol

Question 32

You are in the emergency room and you realize that the patient has hyperkalemia. You decide to lower the serum K+ levels quickly. Your choice will be infusion of an IV solution containing: A. NaCl and Glucose B. Insulin C. Glucagon and Glucose D. Insulin and Glucose E. Epinephrine and Glucose

Answer 32

D. Insulin and Glucose