ch 13

Question 1

cell signaling

Answer 1

cells communicate with environment and each other

Question 2

main stages of cell signaling (4)

Answer 2

stimulus/signal
receptor
signal transduction pathway
response/effector

Question 2

what stimuli prompts cell signaling

Answer 2

deviation from homeostasis

Question 3

types of signals

Answer 3

electrical
mechanical
light
temperature
chemical

Question 4

electrical signals

Answer 4

sent in the form of ions

Question 5

examples of electrical signals

Answer 5

voltage-gated channels
neurons firing

Question 6

mechanical signals

Answer 6

stretching/pulling/pushing forces can also be signals

Question 7

examples of mechanical signals

Answer 7

mechanically gated channels
baroreceptors

Question 8

baroreceptors

Answer 8

protein receptors in vessels that sense and correct blood pressure

Question 9

light signals

Answer 9

light conveys information

Question 10

examples of light signals

Answer 10

photoreceptors in the eye

Question 11

photoreceptors

Answer 11

cells that convert light into electrical information

Question 12

temperature signals

Answer 12

temperature conveys information

Question 13

temperature examples

Answer 13

thermoreceptors in the skin

Question 14

thermoreceptor

Answer 14

parts of sensory neurons that help sense changes in temp

Question 15

chemical signals

Answer 15

nutrients
hormones
proteins
neurotransmitters
more

Question 16

ligand

Answer 16

chemical signal that binds to a particular receptor

Question 17

different types of cell-cell communication

Answer 17

endocrine s.
paracrine s.
autocrine s.
direct s.

Question 18

endocrine signaling

Answer 18

signaling molecules secreted by specialized cells
molecule travels through bloodstream
molecule binds and alters distant target cell

Question 19

paracrine signaling

Answer 19

signaling molecules are secreted
molecule binds to NEARBY cell

Question 20

autocrine signaling

Answer 20

signaling molecules are secreted
molecule binds to the cell that secreted it

Question 21

direct signaling

Answer 21

signal molecule extends from one cell
molecule binds to adjacent cell
the two cells are in physical content

Question 22

types of receptors (2)

Answer 22

intracellular receptors
membrane-bound receptors

Question 23

intracellular receptors

Answer 23

receptor inside the target cell
ex. estrogen receptor

Question 24

membrane-bound receptors

Answer 24

transmembrane proteins

Question 25

dimerize

Answer 25

receptors are brought together by ligand

Question 26

autophosphorylation

Answer 26

phosphorylation of self

Question 27

G-coupled protein receptors (GPCRs)

Answer 27

spans cell membrane major drug target associated with G proteins

Question 28

G-coupled protein receptors (GPCRs) mechanism

Answer 28

1) off- no ligand bound, GDP bound to alpha subunit 2) activation- ligand binds, GDP exchanged for GTP, alpha dissociates from gamma/beta 3) signal propagation- alpha and gamma/beta subunits interact with other proteins, those proteins propagate signal

Question 29

signal transduction pathways

Answer 29

cascade of events between signal and response involves proteins activating other proteins

Question 30

response

Answer 30

occurs to address the initial stimulus and return to homeostasis

Question 31

glucocorticoids

Answer 31

stress hormones cause cells to increase metabolism and more brain tells kidney to release them

Question 32

glucocorticoids signaling pathway

Answer 32

1) glucocorticoids travel through the membrane 2) bind to intracellular glucocorticoid receptor 3) releases receptor from its repressor protein 4) receptors dimerize and go to nucleus 5) they act as transcription factor to activate genes involved in stress hormones

Question 33

JAK/STAT signaling

Answer 33

activates immune cells

Question 34

JAK/STAT signaling pathway

Answer 34

1) cytokine binds outside of cell 2) causes receptors to dimerize 3) receptors activate JAK proteins 4) JAK proteins phosphorylate STAT proteins 5) STAT proteins dimerize and go to nucleus 6) acts as transcription factor to activate immune cells

Question 35

TNF-(alpha) signaling

Answer 35

helps the body respond to pathogens and inflammation

Question 36

TNF-(alpha) signaling pathway

Answer 36

1) TNF-(alpha) protein binds TNF receptor 2) activates cytosolic proteins, which phosphorylate lKB 3) lKB gets degraded 4) this releases NF-KB, which goes to the nucleus 5) acts as transcription factor 6) activates genes involved in inflammation and immunity

Question 37

feedback loops

Answer 37

they produce something that inhibits themselves