cell signalling

Question 1

name the 3 steps in cell signalling

Answer 1

binding, transduction, response

Question 2

what are the 5 types of intercellular communication

Answer 2

autocrine, paracrine, contact-dependent, neuronal and endocrine

Question 3

describe autocrine communication

Answer 3

cell-same type of cell, nearby.

Question 4

describe contact-dependent communication

Answer 4

No secretions. cell signal on membrane connects directly with receptor on neighbouring cell

Question 5

describe 3 things about paracrine signalling

Answer 5

1) signals secreted
2) short distance
3) can be local mediators involved

Question 6

describe the 2 long range cell-cell communication

Answer 6

1) neuronal - action potential along neurone, chemical transmitters are released into synapses and bind to receptors on the target cell
2) endocrine - signals (eg insulin) are secreted into the blood stream where they can travel long distances to target cells

Question 7

what happens inside a cell when a signalling chemical binds to a receptor in the membrane?

Answer 7

Question 8

what might cell signals provoke (3)

Answer 8

survival, division, differentiation, apoptosis

Question 9

what does ACH provoke in cardiac muscle?

Answer 9

hyperpolarisation leading to bradycardia

Question 10

what does ACH do in skeletal muscle

Answer 10

depolarisation -> contraction

Question 11

what sort of ACH receptors does cardiac muscle have?

Answer 11

muscarinic ACH receptors

Question 12

what sort of receptors are muscarinic ACH receptors

Answer 12

G protein coupled

Question 13

what are nicotinic ACH receptors

Answer 13

non-selective cation ion channels

Question 14

where can you find nicotinic ACH receptors?

Answer 14

skeletal muscle

Question 15

name the factors that can alter an intercellular response to a signal binding to the protein

Answer 15

type of cell, type of receptor, type of secondary messenger/cascade

Question 16

what are the 5 parts of the cell signalling pathway

Answer 16

1) signalling molecule
2) receptor
3) 2ary messengers
4) transcription factors
5) cellular effects

Question 17

at what point in the cell signalling pathway can mutations have effect?

Answer 17

any

Question 18

describe cAMP pathway

Answer 18

1) hormone (eg adrenaline)
2) GPCR
3) adenylyl cyclase->PKA-> phosphorylation of kinases
4) CREB
5) cell growth/cell cycle progression/ hormone release

Question 19

where are Ca2+ ions usual stored?

Answer 19

ER or cytoplasm

Question 20

what do protein kinases do

Answer 20

phosphorylate proteins using a phosphate group from ATP

Question 20

what do protein kinases do

Answer 20

phosphorylate proteins using a phosphate group from ATP

Question 21

which molecule dephosphorylates proteins

Answer 21

phosphatase enzyme

Question 22

what is a phosphorylation cascade

Answer 22

intracellular pathway. phosphorylated proteins are themselves protein kinases so they keep the phosphorylation going until the desired cell action is achieved

Question 23

what 2 pathways are activated by insulin binding to the cell membrane?

Answer 23

MAP kinase
PI3 kinase

Question 24

what receptor does insulin bind to?

Answer 24

tyrosine kinase receptor

Question 25

What does PI3 pathway lead to?

Answer 25

GLUT4 channels go from vesicle in cytoplasm into the membrane
synthesis of lipids, proteins and glycogen
cell survival/proliferation

Question 26

what does MAP kinase pathway do

Answer 26

cell growth/proliferation/gene expression

Question 27

PI3 kinase pathway is inhibited by?

Answer 27

++fatty acids

Question 28

describe the damage in stroke

Answer 28

1ary: blood vessel blockage causes death of nearby cells because of reduced bloodflow
2ary: neurotransomitter GLUTAMATE is released and through EXCITOTOXICITY spreads throughout the tissue, killing calls -> widespread brain damage

Question 29

What would happen if tyrosine kinase receptor doesn’t need the growth factor to be activated

Answer 29

too much phosphorylation inside the cell; MAPK and PI3K pathways always working; too much proliferation, cancer