C16 Cell Communication

Question 1

Four types of signals

Answer 1

endocrine, paracrine, neuronal, contact-dependent

Question 2

endocrine

Answer 2

secretes hormones into bloodstream

Question 3

paracrine

Answer 3

signal induces changes in nearby cells

Question 4

Steroid hormones are a type of ? receptors

Answer 4

intracellular

Question 5

cortisol pathway

Answer 5

cortisol readily flows into cell, binds to nuclear receptor protein and induces conformation change to activate it. complex moves into nucleus and binds to regulatory region of target gene to activate

Question 6

two typers of molecular switches

Answer 6

signaling by phosphorylation (activates kinase). signaling by GTP-binding protein.

Question 7

Activated G protein subunits

Answer 7

alpha and beta-gamma complex

Question 8

Three types of cell-surface receptors

Answer 8

ion-channel-linked, g-protein-linked, enzyme-linked

Question 9

Nitric oxide

Answer 9

diffusible signalling molecule. Activated NO synthase produces NO from arginine and causes relaxation of smooth muscle

Question 10

G-proteins can activate ? and ? proteins

Answer 10

ion channel and enzymes

Question 11

adenylyl cyclase is activated by a G-protein linked receptor to make ?

Answer 11

cAMP

Question 12

serotonin increases ? in nerve cell

Answer 12

cAMP

Question 13

Fertilization of an egg triggers wave of ? that initiates development

Answer 13

Ca++

Question 14

largest class of enzyme linked receptors

Answer 14

tyrosine kinases

Question 15

tyrosine kinases

Answer 15

signal activates kinase, autophosphorylating each receptor. phosphates become binding sites for other intracellular signaling proteins

Question 16

constitutively active ras mutant cannot hydrolyze GTP causing

Answer 16

continual growth

Question 17

growth stimulating factors

Answer 17

mitogens

Question 18

MAP kinases

Answer 18

ras activated phosphorylation cascade that activates many other kinases. phosphorylates and activates many proteins

Question 19

akt function

Answer 19

suppresses cell death by BAD and inhibits apoptosis by activating Bcl2

Question 20

akt promotes cell growth by activating ?

Answer 20

kinase tor

Question 21

Rapid gene activation pathways

Answer 21

cytokines and tgf-beta

Question 22

cytokine function

Answer 22

activate jak/stat pathway that can rapidly activate gene expresion

Question 23

tgf-beta function

Answer 23

girectly activate SMADs

Question 24

NO pathway summary

Answer 24

ca++ activates no synthase. no synthase makes no from arginine. no diffuses into other cell and triggers guanylyl cyclase to make cGMP which promotes relaxation

Question 25

heart muscle contraction pathway summary

Answer 25

acetylcholine binds to gprotein. activated betagamma complex opens ca++ channel casuing heart contraction. k+ closes with alpha ATP hydrolysis and binding to betagamma

Question 26

glucose production pathway summary

Answer 26

adrenaline binds to gprotein. alpha subunit activates adenylyl cyclase to make cAMP. cAMP activates PKA initiating a phosphorylation cascade ultimately activating glycogen phosphorylase.