Cellular Messengers

Question 1

Path of LS Messengers:

Answer 1

Leave the blood –> Diffuse through cell membrane and cytoplasm –> bind w/receptors in nucleus or cytosol –> receptor/messenger complex causes DNA–>RNA–>proteins coded for by messenger

Question 2

Path of WS Messengers:

Answer 2

WS –> Membrane receptor –> Second Messenger that is released INSIDE the cell –> Cellular Response

Question 3

For Membrane Enzyme, Adenyl Cyclase: What is the 2nd Messenger / Associated Kinase?

Answer 3

cAMP / Protein Kinase A or other cAMP dependent

Question 4

For Membrane Enzyme Guanylyl Cyclase: What is the 2nd Messenger / Associated Kinase?

Answer 4

gAMP / Protein Kinase G or other gAMP dependent

Question 5

For Membrane Enzyme Phospholipase C: What is the 2nd Messenger / Associated Kinase?

Answer 5

DAG, IP3 (regulate intercellular calcium release) / Calmodulin (activated by calcium)

Question 6

For Membrane Enzyme Phospholipase A2: What is the 2nd Messenger / Associated Enzymes?

Answer 6

Arachidonic Acid –> Eicosinoids / COX, LOX

Question 7

Most prevalent ion channels & which way to they ions flow through them?

Answer 7

Sodium IN, Chloride IN, Calcium IN, Potassium OUT

Question 8

Primary Active Transport Pumps & which way do they pump ions?

Answer 8

H+ OUT, Calcium OUT, 3 Na OUT/2 K in

Question 9

Facilitated Diffusion:

Answer 9

Glucose in

Question 10

List the most prevalent secondary active transporters / which way to ions flow?

Answer 10

Amino acids flow IN with sodium / Protons flow OUT against sodium / Calcium flows OUT against sodium / Chloride flows IN against bicarb flowing out

Question 11

Which is more common WS messengers or LS messengers?

Answer 11

WS

Question 12

Use Norepinephrine to show why the receptor matters more than the messenger:

Answer 12

In vessels, when NE binds to adrenergic receptor, it causes contraction of blood vessel. When NE binds to receptor on pancreas, it causes decrease in insulin secretion.

Question 13

4 Categories of Signal Transduction Pathways for WS Messages:

Answer 13

Ligand-gated ion channels / Enzymes (receptors tyrosine kinases) / Activate cytoplasmic JAK kinases / G-Protein coupled receptors

Question 14

Describe Ligand-Gated Ion Channels / What ion usually acts as the 2nd messenger?

Answer 14

Receptor is attached to ion channel. When messenger binds, channel opens / Calcium

Question 15

Describe steps of Tyrosine Kinases as plasma membrane receptors:

Answer 15

Receptor is attached to tyrosine kinase. 1st messenger binds –> autophosphorylation of tyrosine group –> phosphorylated group serves as dock for cytoplasmic protein –> docking proteins binds/ activate other proteins

Question 16

JAK Kinase complexed with receptors:

Answer 16

1st messenger binds to receptor / JAK kinase complex –> JAK kinase phosphorylates proteins –> synthesis of new proteins

Question 17

Most Common: Receptors coupled with G Proteins:

Answer 17

G protein complexed w/receptor. Receptor activation –> GTP binds to alpha subunit –> alpha subunit activates ion channel or enzyme

Question 18

G coupled protein and Adenylyl cylcase –>

Answer 18

cAMP (second messenger); activates cAMP dependent protein kinases

Question 19

What is the most important second messenger system / Why?

Answer 19

cAMP / signal amplification

Question 20

Steps between Adenylyl Cyclase and amplification.

Answer 20

Adenylyl Cyclase –> cAMP (2nd messenger) –> cAMP dependent PKAs –> Enzymes –> phosphorylated enzymes

Question 21

Membrane Enzyme: Adenyl Cyclase: Second Messenger / Associated Kinase

Answer 21

cAMP / PKA

Question 22

Membrane Enzyme: Guanyl Cyclase: Second Messenger / Associated Kinase;

Answer 22

gAMP / PKG

Question 23

Membrane Enzyme: Phospholipase C: Second Messenger / what do they regulate / Associated Kinase:

Answer 23

DAG, IP3 regulating / CALCIUM / Calmodulin-dependent or PKC

Question 24

Membrane Enzyme: Phosphlipase A: Second Messenger / Associated kinase?

Answer 24

Arachadonic Acid -> Eicosanoid (PGI, TXA) / COX, LOX