Chapter 7

Question 1

direct contact

Answer 1

channels linking cytoplasm and exchange molecules and ions directly

Question 2

local signaling

Answer 2

molecule diffuses into aqueous area around cells
local regulator-signal molecule
paracine regulation-acts on nearby cell
autocrine regulation-acts on cell that produces it

Question 3

long distance signaling

Answer 3

release long term signaling molecule called hormone

enters circulatory system and then travels to target cells

Question 4

reception

Answer 4

binding of signal molecule with specific receptor of target cells
nonpolar molecules receptors in cell
polar receptors are on plasma membrane

Question 5

transduction

Answer 5

signal changes into a signaling cascade of reactions that cause cellular response

Question 6

protein kinases

Answer 6

enzymes that transfer a phosphate group from atp to one or more sites on a protein

Question 7

protein phosphatases

Answer 7

remove phosphate groups from target proteins

Question 8

amplification

Answer 8

increase in the magnitude of each step as a signal transduction pathway proceeds

Question 9

receptor tyrosine kinase

Answer 9

have own protein kinase activity on cytoplasm end of protein

Question 10

g protein coupled receptors

Answer 10

respond to signal by activating an inner protein called a g protein

Question 11

first messenger

Answer 11

extracellular signal molecule

Question 12

effector

Answer 12

gtp bound subunit that breaks off and binds to a plasm membrane associated membrane associated enzyme

Question 13

second messenger

Answer 13

nonprotein molecules

Question 14

cyclic amp

Answer 14

small water soluble molecule derived from atp that activates protein kinases that add phosphate groups to target proteins

Question 15

inositol triphosphate

Answer 15

small water soluble molecule that rapidly diffuses through cytoplasm
activated transport proteins in the er which release ca2+

Question 16

diacylglycerol

Answer 16

hydrophobic so it remains and functions in the plasma membrane
with release of ca, activates protein that brings about cellular effects

Question 17

steroid hormone receptors

Answer 17

control proteins that turn on specific gens when they are activated by binding a signal molecule

Question 18

cross talk

Answer 18

interaction by which signal pathways communicate with one another to integrate their responses to cellular signals