Stas - signalling and what have you Flashcards
What are the types of chemical transport
Diffusion
Osmosis
Facilitated transport
Active transport
Give some types of chemical receptors and their response times
> Channel linked receptor (milliseconds)
G-protein coupled receptor (Seconds)
Kinase-linked receptor (Minutes)
Steroid receptor (hours)
Which receptor is
a) Ionotropic
b) Metabotropic
Ionotropic = Channel linked receptor (e.g. nicotinic receptor)
Metabotropic = G-protein coupled receptor
(eg muscarinic receptor)
What happens inside the cell after activation of a kinase-linked receptor before a cellular response happens
e.g. Insulin
Protein phosphorylation
What are the differences between ionotropic and metabotropic receptors?
Ionotropic receptors are molecules that can open or close to allow smaller particles such as ions to flow in and out of cells (lingand-gated transmembrane ion channels)
Metabotropic receptors are linked to a G-protein/enzyme, which is activated upon ligand binding and activates a secondary messenger such as an ion channel
Glutamate receptors and tyrpsine kinase receptors are metabotropic receptors
Give an example of direct cell to cell contact
adhesion molecules
Give an example of secreted ligands
- netrins
- neurotransmitters
- trophic factors etc.
What are the 2 main types of synaptic transmission
Electrical and Chemical
Give an example of an excitatory (spiny) and inhibitory (non spiny) transmitter
Excitatory = glutamate/aspartate
Inhibitory = GABA/glycine
What types of metabotropic receptors are INSIDE a cell
receptors for steroids and vitamins e.t.c
The _______ surrounding axons is critical to the propagation of action potentials. It essentially serves to maintain conductivity; without it, action potentials would travel much more slowly
Myelin sheith
What is the ligand for the NMDA receptor and what is it’s function?
Glutamate
Controlls synaptic plasticity and memory
The NMDAR is a specific type of ______ glutamate receptor
The NMDAR is a specific type of ionotropic glutamate receptor
The NMDA receptor forms a ______mer between two Glu__ and two Glu__ subunits
The NMDA receptor forms a heterotetramer between two GluN1 and two GluN2 subunits wo GluN2 subunits
NMDA receptor:
The extracellular domain contains two globular structures: a _____ domain and a _____ domain. NR1 subunits bind the co-agonist ____ and NR2 subunits bind the neurotransmitter ______.
The extracellular domain contains two globular structures: a modulatory domain and a ligand-binding domain. NR1 subunits bind the co-agonist glycine and NR2 subunits bind the neurotransmitter glutamate.
NMDA receptor:
Each subunit has an extensive cytoplasmic domain, which contain residues that can be directly modified by a series of protein ____ses and protein _____ses,
Each subunit has an extensive cytoplasmic domain, which contain residues that can be directly modified by a series of protein kinases and protein phosphatases,
____ not only blocks the NMDA channel in a voltage-dependent manner but also potentiates NMDA-induced responses at positive membrane potentials.
Mg2+ not only blocks the NMDA channel in a voltage-dependent manner but also potentiates NMDA-induced responses at positive membrane potentials.
Give some biological functions mediated by G-protein linked receptors
taste, smell, vision… via neurotransmission, cell growth and differentiation, reorganisation of cytoskeleton, intracellular transport and exo/endocytosis
What are the 2 types of G-proteins?
Heteritrimeric and
small g proteins
Give some features of G-proteins
e.g. signal amplification
> slower than ionotropic
offer great environment for regulation
long-lasting with regulated clock option
evolutionary old and >highly conserved
What are small G proteins and their use
Superfamily of “switch” proteins, which are essential regulators of signal transduction leading to organization of the cytoskeleton and cellular traffic.
e.g.
>Ras cell proliferation and differentiation
>regulation of nucleocytoplasmic transport of RNA and proteins during the G1, S, and G2 phases of the cell cycle and microtubule organization during the M phase
What are the components of the EGF transduction pathway
>Small G protein (EGF receptor and Phosphorylated tyrosine kinase domaine >Grb-2 adapter protein >Sos >Ras >GTPase activation protein
What are aniston cells?
hyper specific neurones responsible for memory.
Formed by potentiation of existing synapses and formation of new ones
What is long term potentiation?
a functional alteration in synaptic transmission, which results in a persistent upregulation of synaptic efficacy
