Communication at the Cellular Level

Question 1

when one cell sends a signal to a neighboring cell, the signaling mechanism is called

Answer 1

paracrine

Question 2

which of the following components is the most influential factor in transmitting information from one cell to another

Answer 2

ligand-receptor complex

Question 3

what is endocrine signaling?

Answer 3

cell communication by chemical signals produced by a hormone-producing gland and secreted into the bloodstream

Question 4

what is paracrine signaling?

Answer 4

cell communication by diffusion of chemical signals from neighboring cells

Question 5

what is autocrine signaling?

Answer 5

cell communication by diffusion of chemical signals produced and received by the same cell

Question 6

which type of receptor is located inside the cell rather than in the cell membrane?

Answer 6

nuclear receptor

Question 7

when a ligand binds to an ion-channel receptor, the channel protein opens and what is allowed to enter the cell?

Answer 7

ions

Question 8

what is an example of a nuclear receptor ligand?

Answer 8

testosterone

Question 9

what are 5 different effects that signal transduction can lead to?

Answer 9

• changes in enzyme activity
• changes in cell shape or cytoskeletal organization
• changes in ion permeability
• replication activation
• transcription activation
• controlling gene expression

Question 10

Many signaling molecules are too large or otherwise unable to cross the cell membrane. Some of those molecules transmit their signal through a receptor which transmits the signal into the cell via a second messenger. The second messenger carries the information brought by the extracellular signal into the cytoplasm of the cell to generate a response. If the messenger inside the cell is the second messenger, what is the “first messenger” in a signal transduction pathway?

Answer 10

the signal molecules (ligand)

Question 11

which term best describes the process by which an extracellular signal that does not cross the plasma membrane leads to an intracellular response?

Answer 11

signal transduction

Question 12

GPCRs activate

Answer 12

G proteins

Question 13

what are the 2 mechanisms that regulate the action of cAMP?

Answer 13

enzyme breakdown of cAMP by phosphodiesterase; inhibition of cAMP production via activation of inhibitory Ga proteins

Question 14

which type of receptor requires second messengers for signal transduction?

Answer 14

GPCRs

Question 15

what is the role of the JAK-STAT pathway

Answer 15

inflammation and immune responses

Question 16

What is the role of the Ras-MAP pathway

Answer 16

cell proliferation

Question 17

Imagine it is a busy Saturday morning in the clinic. Amongst your full-booked vaccination and well-check schedule, another patient is squeezed in after the customer service representative saw her rather impressive looking face. Jodi, a 3-year-old female spayed mixed breed dog was stung by a bee while out on a walk. Jodi’s face is swelling, red and itchy. You decide to give her an injection of a glucocorticoid medication, dexamethasone, for immediate relief in the hospital. What type of receptor pathway do glucocorticoid medications bind to?

Answer 17

nuclear receptors

Question 18

The impressive sniffing ability of dogs is a result of the fact that they have almost double the number of olfactory (smelling) receptors than humans. What type of receptor do odor molecules bind to?

Answer 18

GPCRs

Question 19

Mast cell tumors are a common skin cancer in dogs. A drug that is used to treat mast cell tumors is Palladia (toceranib). Palladia is an inhibitor class of antineoplastic (anti-cancer) drug. What kind of receptor pathway do you think is inhibited by Palladia?

Answer 19

enzyme-associated receptors

Question 20

describe the role of a ligand in cell communication

Answer 20

binds to receptors and functions as a signaling molecule

Question 21

what component is the most influential factor in transmitting information from one cell to another?

Answer 21

ligand-receptor complex

Question 22

what is a characteristic of ion-channel receptors that best distinguishes them from enzyme-associated receptors?

Answer 22

allows passage of molecule into the cell

Question 23

what molecule can serve as a second messenger?

Answer 23

calcium ion

Question 24

what term best describes the process by which an extracellular signal that does not cross the plasma membrane leads to an intracellular response?

Answer 24

signal transduction

Question 25

what best describes the action of opioids in regulating cAMP?

Answer 25

inhibition if cAMP production