Chapter 9; Textbook

Question 1

What is paracrine signaling?

Answer 1

Signaling between cells that are close together, uses diffusion through the extracellular matrix

Question 2

What type of responses does paracrine signaling typically elicit?

Answer 2

Quick, short-lasting responses

Question 3

How does paracrine signaling keep signals localized?

Answer 3

Paracrine ligand molecules are normally quickly degraded by enzymes or removed by neighboring cells

Question 4

What’s an example of paracrine signaling?

Answer 4

Nerve cell synapses

Question 5

What is endocrine signaling?

Answer 5

Signaling from distant cells via the bloodstream

Question 6

What type of response does endocrine signaling elicit?

Answer 6

A slower, long-lasting response

Question 7

What are the ligands released during endocrine signaling called?

Answer 7

Hormones

Question 8

What are hormones?

Answer 8

Signaling molecules that are produced in one part of the body but affect other body regions some distance away

Question 9

How do hormones travel?

Answer 9

Through the bloodstream

Question 10

What’s a downside to the movement of hormones via the blood stream?

Answer 10

Hormones become more diluted

Question 11

What is autocrine signaling?

Answer 11

When the target cell is the same (or similar) cell as the signaling cell

Question 12

When is autocrine signaling used?

Answer 12

During the early development of an organism to ensure that cells develop into the correct tissues, to regulate pain sensation and inflammatory responses, and in apoptosis

Question 13

What is direct signaling across gap junctions?

Answer 13

The small, fluid-filled channels (gap junctions) allow intracellular mediators to diffuse between the two cells

Question 14

What do internal receptors do?

Answer 14

They respond to hydrophobic ligand molecules that are able to travel across the plasma membrane

Question 15

What do cell-surface receptors do?

Answer 15

They span the entire plasma membrane and perform a signal transduction, through which an extracellular signal is converted into an intracellular signal

Question 16

What do ion channel-linked receptors do?

Answer 16

They bind a ligand and open a channel through the membrane that allows specific ions to pass through

Question 17

What do g-protein-linked receptors do?

Answer 17

They bind a ligand and activate a membrane protein (G-protein) that then interacts with either an ion channel or an enzyme in the membrane

Question 18

How many transmembrane domains do g-protein-linked have?

Answer 18

7

Question 19

What are enzyme-linked receptors?

Answer 19

Cell-surface receptors with intracellular domains that are associated with an enzyme

Question 20

What can small hydrophobic ligands do?

Answer 20

Directly diffuse through the plasma membrane and interact with internal receptors

Question 21

What makes water-soluble ligands unique?

Answer 21

They can’t pass through the plasma membrane unaided, so they bind to the extracellular domain of cell-surface receptors

Question 22

What is phosphorylation?

Answer 22

One of the most common chemical modifications that occurs in signaling pathways, it adds a phosphate group to a molecule (like a protein)

Question 23

What enzyme is used during phosphorylation?

Answer 23

Kinase

Question 24

What is a second messenger?

Answer 24

It’s a small molecule that propagates a signal after it’s already been initiated, which helps spread a signal through the cytoplasm by altering the behavior of certain cellular proteins

Question 25

What’s an example of a second messenger?

Answer 25

Cyclic AMP (cAMP)

Question 26

What are inositol phospholipids?

Answer 26

Lipids that can also be converted into second messengers

Question 27

What are growth factors?

Answer 27

The ligands that promote cell growth

Question 28

What is quorum sensing?

Answer 28

Bacterial signaling, which detects the number of cells present in the environment

Question 29

What does quorum sending use?

Answer 29

Autoinducers

Question 30

What are autoinducers?

Answer 30

Found in quorum sensing, autoinducers are signaling molecules secreted by bacteria to communicate with other bacteria of the same kind