Chapter 6

Question 1

Ligand gated channel in action

Answer 1

-Messenger bind to receptor protein, non-covalently
-Receptor protein is also a channel
-Bond energy changes protein flexes and the channel can open
-Change in membrane potential
-Going to get Ion Flux

Question 2

Sodium or Potassium Ligand-Gated channel

Answer 2

-Messenger bind to receptor protein, non-covalently
-Receptor protein is also a channel
-Bond energy changes protein flexes and the channel can open
-Change in membrane potential
-Going to get Ion Flux
-Let’s say a sodium channel opens
-Sodium is going to flow in
-Depolarize the cell
-That cell is now different than is way before
-Open a potassium channel get opened
-Potassium will flow out moving with its gradients
-Hyperpolarization

Question 3

How do you close a channel

Answer 3

Get rid of the messenger

Question 4

What happens when a receptor enzyme is activated

Answer 4

Receptor enzymes act as enzymes to alter cytoplasmic proteins

Question 5

Popular enzyme receptor

Answer 5

Kinase Receptors

Question 6

Kinase Receptor Enzyme in action

Answer 6

-First messenger binds non-covalently
-Receptor protein to flex being conveyed through transduction through membrane
-To membrane part of protein that is the kinase
-Kinase Activated
-Phosphate off ATP and put it on a protein
-Covalent Modulation

Question 7

How does GTP-binding proteins work

Answer 7

First messenger binds non-covalently to a surface protein and activates a G-protein that initiates a second messenger that initiates the cell’s response

Question 8

GTP-binding proteins in action

Answer 8

-First messenger binds to receptor non-covalently
-Flexes and pushes G-protein
-Activates an enzyme or opens a channel

Question 9

Cyclic AMP pathway

Answer 9

-Messenger binds to receptor protein, non-covalently
-Receptor protein flexes
-Pushed on G protein
-Activates an enzyme
-Activates Adenylyl cyclase
ATP to cAMP
-cAMP in second messenger
-Inactive cAMP-dependent protein kinase allosteric activated by cAMP
-Active cAMP-dependent protein kinase
-Protein kinase A phosphorylates other proteins through covalent modulation

Question 10

GPCR: Phospholipase C System

Answer 10

 Signal Molecule binds to receptor
 Receptor flexes
 Activates and pushes on G Protein
 Activates an enzyme
* Phospholipase what does it mean
o ase=enzyme
o Acts on phospholipid
 PL-C enzyme
 It attacks membrane phospholipids makes two pieces into diacylglycerol (DAG), which remains in the membrane and IP3, which diffuses into the cytoplasm
* DAG and IP3 is our second messenger
 DAG activates protein kinase C (PK-C), which phosphorylates proteins this is colavlent modulation
 IP3 to the ER and opens a calcium channel, release of CA2++ to the cytoplasm, interacting with the cytoskeleton creating a cellular response

Question 11

Agonist

Answer 11

Chemical messenger that binds to a receptor and triggers a cell’s response

Question 12

Antagonist

Answer 12

Molecule that competes with another for a receptor and binds to the receptor but does not trigger a cellular response

Question 13

What can all have an effect on the messenger

Answer 13

The target receptor can have a different effect
-It is the same messenger but how the receptor reacts to it is different for each

Question 14

Example of receptors getting the same thing but acting different

Answer 14

-Alpha Receptors and Epinephrin close
-Beta Receptors and Epinephrin open

Question 15

After the cell’s response has been initiated, the first messenger must be stopped. Messenger can be

Answer 15

-Degraded by extracellular enzymes
-Endocytosis of receptor-ligand complex
-Going to go to a lysosome and be broken down

Question 16

After the cell’s response has been initiated, the second messenger must also be remove by

Answer 16

-Degradation of the second messenger
-Pumping of ions out of the cytoplasm
-Pump it into the ER or our of the cell completely into the ECF