CS - L1

Question 1

Why is cell signalling needed?

Answer 1

To ensure survival?

Question 2

What is cell signalling?

Answer 2

A complex system of communication

Question 3

What does cell signalling govern?

Answer 3

basic cellular activities and coordinates cell actions

Question 4

Cell signalling affects a cell’s ability to…?

Answer 4

Regulate cellular processes & respond to its environment

Question 5

What is regulation of cell processes and cell signal responses important for?

Answer 5

Development, tissue repair, cell growth/division, immunity, movement and diseases

Question 6

What does cell survival depend on?

Answer 6

Receiving and processing information from the environment

Question 7

A cell is exposed to multiple different extracellular signal molecules - does it respond to them all?

Answer 7

No

Question 8

Why is cell signalling important at an organism level?

Answer 8

development -> specialised cells -> coordinated response

Question 9

What are potential results of defects/dysregulation in signalling pathways?

Answer 9

Diseases - cancer, diabetes, etc.

Question 10

What occurs in the absence of signals

Answer 10

apoptosis

Question 11

Why is constant signalling required?

Answer 11

cell survival

Question 12

What is Wnt signalling involved in?

Answer 12

embryonic development (heart, bone, etc)

Question 13

What occurs if Wnt is disrupted/dysregulated

Answer 13

cancer (colorectal cancer)

Question 14

What determines the type of signalling a cell uses?

Answer 14

distance between the cells

Question 15

What are the 5 basic types of signalling used?

Answer 15

Gap junction, APC , neurotransmitter, auto/paracrine, hormone

Question 16

What are gap junctions

Answer 16

cytoplasmic channels between adjacent cells - connects cytoplasm

Question 17

What does the gap junction do?

Answer 17

maintains homeostasis in connected cells for ion balance & allows passage of signal molecules

Question 18

What does gap junction provide?

Answer 18

metabolic cooperation between adjacent cell

Question 19

What are the receptors required for CD4?

Answer 19

MHC2

Question 20

What is common between autocrine and paracrine signalling

Answer 20

ligands produced by cells that travel through extracellular fluid

Question 21

What cell is the cell signalling to in autocrine?

Answer 21

Itself

Question 22

Give examples of an autocrine signalling

Answer 22

IL-1 secreted by monocytes as a response to external stimuli

Secretion of growth/survival factors by tumour cells

IL-2 in T cells

Question 23

What cell is the cell signalling to in paracrine?

Answer 23

Neighbouring cells

Question 24

Give examples of paracrine signaling

Answer 24

Wnt and hedgehog & inflammatory mediators

Question 25

What is tumour cell migration controlled by?

Answer 25

Paracrine loop

Question 26

What occurs during the paracrine loop?

Answer 26

Tumour Associated Mq make EGF (epidermal growth factor) -> EGF binds to EGFR on invasive breast tumour cell -> Invasive tumour cell makes CSF1 (colony stimulating F1) binds to CSF1R on TAM

Question 27

What do neurotransmitters trigger in cells/target tissues?

Answer 27

Responses

Question 28

Where does the nuerotransmitter go after use?

Answer 28

Remains in the synapse

Question 29

What happens to the neurotransmitter after its been used?

Answer 29

Broken down

Question 30

What determines the specificity of neurone signalling?

Answer 30

synaptic contact between neurone and target cell

Question 31

What is the advantage in neurone signalling compared to direct contact

Answer 31

control the amount of signal travels by inhibition

Question 32

What are the 4 ways cells communicate if they're close to e/o and give examples

Answer 32

contact-dependent (APC & CD4) autocrine signalling (IL2 and CD4) paracrine signalling (TAM and invasive breast tumour cell) Synaptic signalling (neurone & target cell) SOMETIMES, can be distant

Question 33

How do cells communicate long distance

Answer 33

endocrine (hormones) spec. - receptors synaptic signalling spec. - synaptic contacts

Question 34

most signals are ____

Answer 34

chemicals

Question 35

signals act at very ____ conc. -> signal _____

Answer 35

LOW, amplification

Question 36

How are signals recognised?

Answer 36

by receptors with high affinity

Question 37

A cell must respond _____ to a mixture of signals, disregarding some and reacting to others, according to the cell's specialised function

Answer 37

selectively

Question 38

What does the cell need in order to respond to a signal?

Answer 38

A receptor

Question 39

How does the cell restrict the range of signals that can affect it?

Answer 39

By producing a limited set of receptors

Question 40

What are the 3 steps of cell signalling and what factors are involved?

Answer 40

1. reception - > receptors 2. transduction -> signal transducers 3. cell response -> effector proteins

Question 41

What is the function of transducers?

Answer 41

relay, integrate and distribute signals

Question 42

SIgnalling pathways regulate _____ cellular functions

Answer 42

nearly all

Question 43

What are the characteristics of cell signalling?

Answer 43

specificity integration and coordination amplification feedback

Question 44

How is specificity maintained in cell signalling?

Answer 44

receptors.

Question 45

specific receptors are ____ in distinct cell types

Answer 45

expressed

Question 46

What should happen if 2 or more signals have opposite effects on a metabolic pathway?

Answer 46

Outcome result should reflect the integration of these signals

Question 47

Why should the outcome of multiple signals reflect the integration of these signals?

Answer 47

coordinated response

Question 48

What can signalling interfere with?

Answer 48

core physiological processes

Question 49

What's the role of a feedback loop?

Answer 49

desensitisation/adaptation

Question 50

What can the feedback loop do?

Answer 50

Modify the signal and the output to regulate the process

Question 51

What happens during deactivation?

Answer 51

degradation.recycling of molecules

Question 52

What happens during activation?

Answer 52

Adjust sensitivity. under prolonged exposure to reduce cell response's to that level of stimulus

Question 53

What are the 5 basic types of signalling

Answer 53

APC, GAP junction, NT auto/paracrine, endocrine