Cell Signalling Flashcards
Define extracellular mediator
An extracellular stimulus to a cell
What kind of general affects can an extracellular mediator have on a cell after interacting with the plasma membrane?
Modifications of cellular metabolism, function, movement
What kind of general affects can an extracellular mediator have on a cell after interacting with the nuclear membrane?
Modifications to gene expression, development
How do hydrophobic signals interact with the plasma membrane?
Can easily cross it / diffuse across it due to being hydrophobic
List three hydrophobic cell signals
Steroids, retinoids, thyroxine
Steroids, retinoids and thyroxine are all examples of what?
Hydrophobic cell signals
Compare the terms ‘endocrine’ , ‘autocrine’ and ‘paracrine’ when describing cell signals
Endocrine: Long range signals (usually blood borne hormones
Autocrine: Same cell signals (usually growth factors or cytokines
Paracrine: Short range signal from nearby cells (usually growth factors or cytokines)
What general type of effects do hormones have on target cells?
Short-term metabolic effects
What general type of effects do growth factors have on target cells?
Long-term proliferation/developmental effects
What general type of effects do steroid hormones have on target cells?
Long term
What distance do steroid hormones usually act at for cell signalling?
Autocrine (same cell)
What kinds of pathways are GCPR involved in?
Metabolism and movement
Can sometimes be involved in gene expression
Give an example of a receptor with intrinsic serine kinase
TGF-beta receptors (phosphorylate transcription factors)
Give three examples of a receptor with intrinsic tyrosine kinase
Platelet Derived Growth Factor receptor
Insulin receptor
Epidermal Growth Factor receptor
Give an example of a cytokine receptor linked to tyrosine kinase
Cytokine receptor -> Interleukin-3 receptor
Compare receptors with intrinsic kinase activity to receptors linked to tyrosine kinases
Intrinsic: Kinase is part of the monomer activated after dimerisation
Linked: Receptor does not have kinase activity itself but interacts with a seperate kinase associated with the receptor
All other structural domains are the same
What do ion channel receptors such as transient receptor potential (TRP) channels perceive?
Important for temperature perception, thermoperception, chilli
Give an example of an ion channel receptor involved in cell signalling?
Transient receptor potential (TRP) channels
Define ‘second messenger’
Intracellular metabolite or ion, which couples an extracellular stimulus to a physiological response
Why do second messengers need to be small?
So that concentration of them can be increased very quickly, by synthesis, release from a store, and decreased very quickly, by breaking down or sequestering them
