Cell Signaling

Question 1

all cells ____________ from the environment

Answer 1

process information

Question 2

the information that cells process can be _____ or ________

Answer 2

chemical or physical stimulus such as light

Question 3

to respond to a signal a cell must have a specific _______ that can detect it

Answer 3

receptor

Question 4

the sequence of molecular events and chemical reactions that lead to a cells response to a signal

Answer 4

signal transduction pathway

Question 5

is receptor activation a permanent interaction

Answer 5

no

Question 6

is a response temporary

Answer 6

yes

Question 7

what happens to a response so that new signal cells can be received

Answer 7

termination

Question 8

does signaling happen at high population density or low population density

Answer 8

high

Question 9

signals (hormones) travel to distant cells, usually via the circulatory system

Answer 9

endocrine signals

Question 10

these signals affect nearby cells

Answer 10

paracrine signals

Question 11

these signals affect the cells that made them

Answer 11

autocrine signals

Question 12

these signals affect cells touching them

Answer 12

contact dependent

Question 13

list the signals in order from greatest distance to lowest distance

Answer 13

endocrine
paracrine
autocrine
contact dependent

Question 14

what is a signaling molecule

Answer 14

a hormone ex. insulin

Question 15

what system does the paracrine signals affect

Answer 15

nervous system

Question 16

what system does the autocrine signals affect

Answer 16

bacteria

Question 17

what are the two types of cell signaling receptors

Answer 17

1. membrane receptors
2. intracellular receptors

Question 18

these receptors are in the plasma membrane and bind polar ligands (signals)

Answer 18

membrane receptors

Question 19

these receptors are in the cytoplasm and bind non polar ligands that can diffuse across the PM

Answer 19

intracellular/ cytoplasmic receptors

Question 20

receptor proteins have very ________ binding sites for chemical signals or ligands

Answer 20

specific

Question 21

binding the ligand causes the receptor protein to

Answer 21

change shape or conformation

Question 22

the binding is ______ and the ligand is _________

Answer 22

reversible
not altered

Question 23

can inhibitors bind to receptor proteins

Answer 23

yes

Question 24

_______ binds to a receptor on nerve cells, initiating a signal transduction pathway the reduces brain activity

Answer 24

adenosine

Question 25

__________ is similar in structure to adenosine and binds to adenosine receptors blocking their activity (binds receptor but doesn't activate it)

Answer 25

caffeine

Question 26

these bind heterotrimeric G proteins and ligand boning to GPCRs activates G proteins

Answer 26

G protein coupled receptors GPCR

Question 27

these are membranes associated proteins with three subunits and bind GDP (inactive) or GTP (active)

Answer 27

heterotrimeric G proteins

Question 28

is RAS-GTP it is _______

Answer 28

active and activates something in the cell

Question 29

if RAS-GDP it is ________

Answer 29

inactive

Question 30

GTP found alpha-subunit separates from the other subunits and encounters an ___________

Answer 30

effector protein

Question 31

if adrenaline is the signal the effector is __________

Answer 31

adenylycyclase

Question 32

binding _________ the effector which causes a ______ in cell function

Answer 32

activates change

Question 33

GTP is ________ back to GDP and ________ turn themselves off (termination)

Answer 33

hydrolyzed GTPases

Question 34

ATP is a ________

Answer 34

nucleotide

Question 35

the enzyme _________ catalyzes the formation of cAMP to ATP

Answer 35

adenylyl cyclase

Question 36

what is the first messenger

Answer 36

ligand signal

Question 37

what is the second messenger

Answer 37

a small water soluble nonprotein molecule relays the initial signal to target molecules inside the cell

Question 38

adrenaline binding to a membrane receptor causes production of a small molecule _____ which diffuses through the cytoplasm to indirectly activate the phosphorylase

Answer 38

cAMP

Question 39

affect many processes in the cell amplify the signal regulate targe enzymes

Answer 39

second messengers

Question 40

1 molecule of adrenaline creates _______ of glucose molecules

Answer 40

1000's

Question 41

what is the first step in termination

Answer 41

the signal molecule adrenaline detaches from the receptor

Question 42

what is the second step in termination

Answer 42

within a very short period of time an activated G protein deactivates itself

Question 43

what is the third step in termination

Answer 43

enzymes in the cytosol specifically degrade cAMP which stops the phosphorylation and activation of target proteins

Question 44

what is the fourth step in termination

Answer 44

phosphatases remove phosphate groups from proteins

Question 45

these receptors catalyze phosphorylation of themselves and or other proteins

Answer 45

protein kinase receptors

Question 46

the _______ receptor phosphorylates itself and other insulin response substrates and initials glucose transporter insertion into the plasma membrane

Answer 46

insulin

Question 47

2 subunits come together in

Answer 47

dimemerization

Question 48

what does activates a _______

Answer 48

GTPase (RAS)

Question 49

human cancer cells have an ______ form of the monomeric G protein Ras and the protein is ________ activated causing _______ continuous cell division

Answer 49

abnormal permanently activated continuous

Question 50

cancer cells having too many protein kinase receptors which results in overreaction on the ______ kinase signaling pathway and _______ cell division

Answer 50

MAP increased

Question 51

what protein kinase is used as a breast cancer treatment

Answer 51

herceptin

Question 52

channel proteins that allow ions to enter or leave a cell

Answer 52

ion channel receptors

Question 53

signals for ion channel receptors

Answer 53

chemical ligands (hormones) sensory stimuli (light) electric charge differences

Question 54

what are some effects of a signal

Answer 54

opening ion channels changing enzyme activity differential gene transcription

Question 55

can multiple signaling pathways be active in a cell at one time

Answer 55

yes

Question 56

can signaling pathways intersect

Answer 56

yes

Question 57

can the same signaling pathway have different function in different cells

Answer 57

yes