Session 1: Biological Signalling Molecules Flashcards
What are the 3 main extracellular signalling groups?
Endocrine
Paracrine
Autocrine
TRUE OR FALSE: endocrine signalling molecules usually act over long distances throughout the whole body.
TRUE
Name 3 categories of endocrine signalling molecules.
- Amine hormone
- Peptide hormone/ protein hormone
- Steroid hormone
Where is the receptor location for amine/protein endocrine hormones?
Plasma membrane
Where is the receptor located for steroid hormones?
Cytosolic or nuclear
Define paracrine signalling
From cell to cell (or cells within nearby volume)
Define autocrine signalling
Cells respond to signalling molecules preocupes and released by themselves
Name 4 signalling molecule targets.
- Receptors
- Ion channels
- Transporters
- Enzymes
Name 4 signalling molecule receptors.
- Kinase linked receptors
- Ion channels (ligand gated)
- Nuclear /intracellular
- G-protein coupled receptors
How do kinase linked receptors work?
Act via phosphorylation of specific groups, which sets into motion a signalling cascade leading to gene transcription
How do Ion gated ligand channels work?
Voltage change occurs which results in an action potential
How do nuclear/ intracellular receptors work?
Lipid soluble steroid signalling molecule required. Complex migrates to the nucleus where it binds to a transcription factor.
How do GPCR receptors work?
Three major types: Gs, Gi, Gq which activate different intracellular signalling routes
What is the function of ion channels?
Selectively allow ion current to flow across the plasma membrane down its concentration gradient.
What do transporters do?
Use ATP or a pre-existing ion gradient to transport highly polar molecules across the membrane.
