cell communications

Question 1

all organisms respond to which 8 stimuli?

Answer 1

light, temperature, sound, touch, magnetic fields, gravity, pH and chemicals

Question 2

cells in a multicellular organisms send signals and which signals can they be

Answer 2

proteins, peptides amino acids, nucleotides, steroids, fatty acid derivatives or gases

Question 3

what converts the extracellular signal to the intracellular signalling molecules

Answer 3

receptors

Question 4

what is signal transduction

Answer 4

conversion of one type of signal to another

Question 5

cell signalling 3 phases

Answer 5

reception, transduction and response

Question 6

signals can act over a ______ or ______ range

Answer 6

long or short

Question 7

what are the 4 types of signals

Answer 7

endocrine
paracrine
synaptic
contact-dependent

Question 8

what are endocrine signals and how to they act

Answer 8

act over long ranges and are hormones
- remote signals

Question 9

what do endocrine signals target

Answer 9

distant cells

Question 10

what do endocrine signals transported by

Answer 10

circulatory system

Question 11

what ate endocrine signals secreted by

Answer 11

endocrine glands

Question 12

how does paracrine, synaptic and contact-dependent act

Answer 12

over short range (acct locally)

Question 13

some examples of locally acting signal molecules and actions?

Answer 13

growth factors (stimulates many cell types), inflammatory factors (causes blood vessels to dilate) and gases (smooth muscle cells to relax)

Question 14

what does each cell respond to

Answer 14

limited set of extracellular signals

Question 15

what do cells have that are different?

Answer 15

sets of receptors and signal transduction pathways

Question 16

what does signal interpretation depend on?

Answer 16

receptor, intracellular effector proteins and other signals received by cell

Question 17

chemical signals instruct cells to _____?

Answer 17

survive, grow, divide or differentiate

Question 18

what are examples of fast cell responses (< sec to mins)

Answer 18

change in cell movement, cell shape, metabolism and secretion

Question 19

what are examples of slow cell responses (mins to hrs)

Answer 19

cell differentiation, division and growth

Question 20

are cell responses involving gene expression are slow or fast?

Answer 20

slow

Question 21

what do signal molecules bind to

Answer 21

cell-surface receptors or intracellular receptors

Question 22

what do extracellular signals molecules that bind to cell-surface receptors look like?

Answer 22

hydrophilic and large

Question 23

what do extracellular signals molecules that bind to intracellular receptors look like?

Answer 23

small, hydrophobic, extracellular signal cross membrane

Question 24

where ate intracellular receptors bonded to

Answer 24

cytosol or nucleus

Question 25

what examples bind to intracellular receptors

Answer 25

steroid hormones such as cortisol cortisone enters cytoplasm and binds to receptor receptor changes shape and releases chaperone receptor and cortisol ligand to enter nucleus

Question 26

what dissolved gases enter cell and activate intracellular enzymes and how

Answer 26

nitrous oxide - diffuses across membrane and directly regulate the activity of an enzyme

Question 27

what does NO trigger

Answer 27

smooth muscle relaxation in blood-vessel wall

Question 28

what do cell-surface receptors create

Answer 28

new intracellular signals

Question 29

what can intracellular signalling molecules be

Answer 29

proteins or small messenger molecules

Question 30

what do effector proteins do

Answer 30

directly affect the behaviour of the target cell

Question 31

what do intracellular signalling proteins do to the incoming signal

Answer 31

relay, amplify, integrate and distribute

Question 32

what is signalling relay analogous to

Answer 32

relay race inside cell

Question 33

what is amplified inside the cell

Answer 33

extracellular signal

Question 34

what is the incoming signal distributed to

Answer 34

effector proteins

Question 35

when does a cross talk occur

Answer 35

between different intracellular signalling molecules

Question 36

what is the activity of proteins and enzymes in a signalling pathways regulated positively or negative by a ???

Answer 36

feedback mechanism

Question 37

some intracellular signalling proteins act as molecular switches

Answer 37

true (fluctuate between inactive and active)

Question 38

what happens in an activated state

Answer 38

proteins stimulate/suppress other proteins

Question 39

some molecular switches are activated by what and how (P)

Answer 39

phosphorylation by protein kinases inactivated by dephospho rylation by protein phosphatases

Question 40

2 main types of protein kinases

Answer 40

serine/threonine kinases and tyrosine kinases

Question 41

some molecular switches are activated by what and how (G)

Answer 41

GTP binding

Question 42

cell-surface receptors 3 main classes

Answer 42

ion-channel-coupled receptors (ligand-gated ion channels) G-protein-coupled receptors enzyme-coupled receptors

Question 43

what is GPCRs

Answer 43

largest family of receptors (more than 700 types)

Question 44

what do stimulation of GPCRs activates

Answer 44

G-protein subunits

Question 45

what are G protein activated by

Answer 45

set of receptors and activates set of target proteins

Question 46

the g-protein is a

Answer 46

molecules switch (switches itself off)

Question 47

what does acetylcholine signal do?

Answer 47

acetylcholine signal transacted to k+ channel and slows down heartbeat

Question 48

2 most frequent target enzymes for G proteins

Answer 48

adenylyl cyclase phospholipase C

Question 49

GCPRs activate 2 principal

Answer 49

signal transduction pathways

Question 50

adenylyl cyclase generates

Answer 50

cAMP

Question 51

how is cyclic amp generated and degraded?

Answer 51

generated = adenylyl cyclase degraded = cyclic amp phosphodiesterase

Question 52

cAMP signalling pathways activates??

Answer 52

gene transcription

Question 53

what is epinephrine

Answer 53

adrenaline

Question 54

what is related to door perception

Answer 54

GPCRs and cAMP signaling

Question 55

what does the phosphatidylinositol signalling pathways trigger

Answer 55

rise in intracellular ca2+

Question 56

what leads to saliva secretion

Answer 56

phosphatidylinositol signaling pathway

Question 57

calcium binding changes shape of

Answer 57

calmodulin protein

Question 58

what relates to taste perception

Answer 58

GPCRs and phosphatidylinositol signaling

Question 59

five taste classes

Answer 59

sweet, salty, sour, bitter and umami

Question 60

what taste is detected by GPCRs

Answer 60

sweet, umami and bitter

Question 61

what is GCPRs responsible for

Answer 61

light detection in rod cells in retina

Question 62

signals binding RTKs are

Answer 62

growth factors and hormones

Question 63

2 signalling pathways activated by RTKs

Answer 63

ras/mark signaling pi3k/akt signaling

Question 64

RAS is a

Answer 64

G protein and molecular switch

Question 65

Was activated a

Answer 65

map-kinase signalling module

Question 66

activated AKT promotes

Answer 66

cell survival

Question 67

how do AKT stimulates cells to grow

Answer 67

size by activating the serine kinase TOR

Question 68

signal transduction pathways are

Answer 68

interconnected