Cell signaling

Question 1

Example of gap junction signaling

Answer 1

Glucagon receptors on liver cells are not evenly distributed

Connexins disperse glucagon molecules to coordinate cAMP signaling

Question 2

How many connexin molecules make a half pore?

Answer 2

6

Question 3

Example of contact-dependent signaling

Answer 3

Glycoproteins of leukocyte adhere to receptors on endothelial cells to guide them to injury site

Question 4

What transmembrane protein is responsible for leukocytes binding to endothelial cells?

Answer 4

Integrins

Question 5

Example of signaling with secreted molecules

Answer 5

ACh to adrenergic receptors

Question 6

What is endocrine signaling?

Answer 6

Molecules transported by the bloodstream

Question 7

What is paracrine signaling?

Answer 7

Molecules diffuse to nearby cells

Question 8

What is autocrine signaling?

Answer 8

Molecules diffuse to same type of cell or to upregulate producing cell

Question 9

Name a molecule that uses endocrine signaling

Answer 9

Anti-diuretic hormone

Question 10

What is the function of ADH?

Answer 10

Low blood pressure (vasoconstriction)

High blood osmolarity (water retention)

Question 11

What are the receptors of ADH?

Answer 11

Vasopressin 1 - smooth muscle cells, arteries

Vasopressin 2 - Kidney collecting ducts

Question 12

Name a molecule that uses Paracrine signaling

Answer 12

Nitric oxide

Question 13

What is the function of nitric oxide?

Answer 13

Vasodilation during inflammation

Question 14

What enzyme is activated after NO binds to histamine receptors?

Answer 14

Guanylyl cyclase

Question 15

Name a molecule that uses neuronal signaling

Answer 15

Acetylcholine

Question 16

What is the function of acetylcholine?

Answer 16

Voluntary muscle contraction

Question 17

What is the receptor for acetycholine?

Answer 17

Nicotinic acetylcholine receptor

Question 18

What is the difference between endocrine and synaptic receptors?

Answer 18

Endocrine receptors need low concentration of molecule to reach many cells

Synaptic receptors need high concentration of molecules to reach specific cells.

Question 19

What is the difference between water-soluble and lipid-soluble receptors?

Answer 19

Extracellular vs intracellular receptors

Question 20

Name a water-soluble signaling molecule

Answer 20

Epinephrine

Question 21

Name a fat-soluble receptor signaling molecule

Answer 21

aldosterone

Question 22

What are the 3 types of target molecules?

Answer 22

Cell surface receptors
Intracellular Receptors
Intracellular enzymes

Question 23

Name a signaling molecule that uses cell-surface receptors

Answer 23

ADH

Question 24

Name a signaling molecule that uses an intracellular receptor

Answer 24

Aldosterone

Question 25

What is the function of aldosterone?

Answer 25

Modulate high K+ in serum by inducing kidney to excrete K+ and retain H2O and Na+

Question 26

Name a signaling molecule that uses intracellular enzymes

Answer 26

Nitric oxide