CMB1004/L14 Cell Communication Flashcards
Where is information transferred during cell signalling? (2)
Environment to cell
Cell to cell
Why is cell signalling used? (2)
Response to signals from environment
Coordinate cell behaviour
Give 5 examples of cell signalling.
Development
Nervous system
Immunology
Physiology
Pharmacology
Cell cycle/DNA repair
Metabolism
Give the 3 steps to a simple signalling pathway.
Signal
Reception
Response
Give the 5 key steps in a signalling pathway.
Signal
Reception
Transduction
Amplification
Response
How can the activity of proteins in a signalling pathway be regulated? (2)
Changing the level of protein (slow)
Changing activity of existing protein (fast)
By what 2 mechanisms can the activity of protein be modified?
Conformational change
Covalent modification e.g. phosphorylation
Give 5 examples of cell signalling methods.
Gap junction
Contact-dependent
Autocrine/paracrine signalling
Endocrine signalling
Synaptic signalling
Describe the gap junction method of cell signalling.
Signalling molecules pass directly from cell to cell through gap junction channels
Describe the contact-dependent method of cell signalling.
Signalling molecule on cell surface interacts directly with receptor on recipient cell
Which kind of cell signalling is particularly important during development?
Contact-dependent
Describe the paracrine signalling method of cell signalling.
Local mediators act on different cell types in close proximity via cell surface receptors
Describe the autocrine signalling method of cell signalling.
‘Self’ signalling in which the cell is able to bind the signal which it secretes
Other cells of same type can bind
What kind of molecules can cross the cell membrane?
Small hydrophobic molecules
What kind of molecules must bind to cell-surface receptors?
Hydrophilic signalling molecules
Describe the change to nuclear hormone receptors when ligand binding occurs. (2)
Conformational change occurs
Receptor-ligand complex regulates transcription of target genes
Give 3 examples of intracellular receptor ligands.
Cortisol
Estradiol
Thyroxine
Testosterone
Vitamin D3
Retinoic acid
Give an example of a ‘no receptor, no response’ situation.
Androgen receptors in androgen sensitivity syndrome
Absence of receptors causes female pattern of development regardless of sex chromosomes
Describe the response of nitric oxide receptors to ligand binding (ACh). (3)
Conformational change
Produces a secondary messenger (cGMP)
Vasodilation
Give the 3 classes of cell surface receptors.
Ion channel coupled
G-protein coupled (GCPRs)
Enzyme coupled
