Topic 8

Question 1

Signaling cell

Answer 1

Releases message

Question 2

Ligand

Answer 2

Sents the message to the receptors on the target cell

Question 3

Target Cell

Answer 3

Receives the message from the Signaling Cell

Question 4

Autocrine

Answer 4

Auto: self
A cell that communicates with itself
-Uses exocytosis and diffusion through extracellular spaces
Target cell and signaling cell are the same cell

Question 5

Direct (via gap junctions or plasmodesmata)

Answer 5

physical connection between the cells
-Target cell and signaling cells are touching through physical contact

Question 6

Paracrine

Answer 6

Para: near or next to
-Target cell is nearby (<20 cells away)
-Uses exocytosis and diffusion through extracellular spaces

Question 7

Endocrine

Answer 7

Endo: inside
-long distance communication
-Target cell is farther (>20 cells away)
-Uses exocytosis and diffusion through extracellular spaces

Question 8

Inactive state

Answer 8

receptor is not triggering response from the cell
-When the voltage-gated channel is blocked and the ions are not even entering the channel (inactive and ready to respond)

-The voltage-gated channel can be open but is blocked at the other end, the ions cannot get through the full channel (Inactive and not ready to respond)

Question 9

Active state

Answer 9

receptor is triggering response from the cell
-the voltage-gated channel is fully open and ions can flow through freely (active, triggering response in target cell)

Question 10

Amino acids bind where?

Answer 10

Bind to the cell surface receptor

Question 11

Cholesterol binds where?

Answer 11

Binds to the internal receptor

Question 12

Peptides bind where?

Answer 12

binds to the cell surface receptor

Question 13

Receptor Tyrosine Kinases

Answer 13

-Tyrosine tells me amino acids are present
-Kinases tells me there is enzyme activity present
-This receptor has tyrosine (amino acids along the chain) that are phosphorylated (phosphate groups added) using ATP (cellular energy)
-Intergral membrane protein that has kinase

Question 14

Tyrosine Kinase Response

Answer 14

Activation of second messenger system which may lead to changes in ion membrane permeability increased or decreased…

Question 15

Transmembrane proteins

Answer 15

Type of membrnae protein that spans across the entire membrane
-Trans: across

Question 16

Receptor

Answer 16

Intergral membrane protein that is also an ion channel

Question 17

Ion channel coupled

Answer 17

this receptor has an ion channel (transport protein) that allows ions/charged atoms through
-Example: Nicotinic Acetycholine Receptors (Ligand Based Receptors)

Question 18

Signal

Answer 18

Highly variable by receptor (voltage, mechanical, ligand, and photo stimuli)
-Example: Acetylcholine
-Usually a Ligand (chemical)

Question 19

Response

Answer 19

Fast, controlled. select ion movement across the membrane, changes proportion of charges

Question 20

G protein (coupled with receptor)

Answer 20

Peripheral protein associated with intracellular surface of plasma membrane
-G protein-coupled/linked receptors, there is a receptor that works closely (right next to each other) with a G protein to do its job

Question 21

Steps of GCPR

Answer 21

1. Ligand Binds to GCPR
   2.GCPR undergoes confirmational change
   3.The alpha subunit exchanges GPP for GTP
   4.Alpha subunit dissociates and regulates target proteins
   5.Target proteins relay signal via secondary messenger system
2. The G protein subunit breaks down GTP into GDP and becomes deactivated
3. Removal or breakdown of ligand from receptor/ or deactivation of secondary messanger system causes subunit to regroup into the inactive timer state

Question 22

Target Cell Receptor Steps

Answer 22

1. Receptor activation leads to activation of second messengers
2. Receptor autophosphorylates
3. Receptor is inactive
4. Receptor dimerizes