Lecture 14 Flashcards
nAchR
Nicotine Acetyl choline receptor
What do these proteins have to function as first?
A receptor before a channel
What is a terminal axon?
Most distal part of pre-synaptic cell
What is the inhibitor Curare?
Plant alkaloid - found in South America.. poison arrows
Partially blocks receptor site.
What is the inhibitor Alpha Bungarotoxin?
Venom from the Southeast Asian banded Krait
High affinity for AchRs (stronger affinity, binds stronger)
95 Amino Acid Sequence
Irreversible Binding
What is a Motor Unit?
A motor neuron and all of the muscle fibres it plugs into
What is a single motor apha neuron
No muscle fibres
Is an inhibitory neuron active?
Yes. Always active - just releases different neurotransmitter.
What is an inward current?
Sodium rushing into the cell.
Where is the cell body?
In the grey matter of the ventral root.
What is the predominant form of neurons operating?
Inhibitory neurons - control
Where is the Alpha Motor Neuron located?
Cell Body (ventral root) of spinal cord
What is an excitatory neurotransmitter?
Glutamate
Where does Glutamate come from?
Upper motor neurons, sensory neurons via Interneurons (cell body confined in grey matter)
What is a primary reflex?
Don’t need the neural impulse to hit the interneuron first
What are inhibitory neurotransmitters?
Glycine and GABA via spinal cord interneurons
What is the purpose of endocytosis?
Obtain cell nutrients, absorb/digest pathogens and cell debris (broken cells)
Where is Pinocytosis seen?
In neuromuscular junction.
How many AcH sites are there on the primary synaptic cleft
20,000 binding sites per micrometer squared
How many subunits in the nAchR
5 protein sub-unit
How many Ach are required per receptor?
2 Ach Are required per receptor.
What is the Alpha Bunagrotoxin?
Venom from a snake, it is an NachR inhibitor, it has a strong affinity for nAchR’s
Where is the single a-motor neuron located?
In the grey matter of the ventral root.
What is an inward current representing?
Sodium flooding into the cell
What might you need in order for an action potential to be reached?
Need two excitatory neurotransmitters working at the same time.
What would an inhibitory neurotransmitter do?
Put it below the resting potential (hyper polarization)
What do excitatory and inhibitory neurotransmitters do?
They work together to put on gas and breaks of an action potential (very controlled)
Where is an alpha motor neuron located?
In the spinal cord, particularly in the your cell body (grey matter)
Where does your excitatory post-synaptic potential come from?
Excitatory neurotransmitters (glutamate)
Where does Glutamate (or excitatory neurotransmitters) come from?
Upper motor neurons, sensory neurons.
How do you get from you sensory neurons to your motor neurons
Via the interneuron
What is the reflex arc?
A reflex arc is a neural pathway that controls a reflex. In vertebrates, most sensory neurons do not pass directly into the brain, but synapse in the spinal cord.
What are inhibitory neurotransmitters?
Glycine and GABA
Where do inhibitory neurotransmitters come from?
Spinal Cord Interneurons
How do cells transport?
Via vesicles budding or by the cytoplasm pinching the cell and is being recycled back into the pre-synaptic membrane
What is the purpose of endocytosis?
Endocytosis is the movement of out to in.
Obtain cell nutrients, absorb/digest pathogens and cell debris
What is Pinocytosis?
A process by which the cell takes in the fluids along with dissolved small molecules.
Where is Pinocytosis seen?
In the neuromuscular junction
What does pinocytosis form?
A endoscope
What is Phagocytosis?
Process by which certain living cells called phagocytes ingest or engulf other cells or particles.
What does Phagocytosis form?
Large endoscope called phagocytes
What is receptor mediated endocytosis?
Endosomes are formed
Involves particle recognition and membrane protein receptors
It concentrates particles to endocytic region of the membrane
What is Clathrin?
A protein concentrated over endocytosis region of the membrane.
What are endoscopes?
Are primarily intracellular sorting organelles. They regulate trafficking of proteins and lipids among other subcellular compartments of the secretory and endocytic pathway, specifically the plasma membrane Golgi, trans-Golgi network (TGN), and vacuoles/lysosomes.
What does Clathrin form?
A clathrin coat
What does Cathrin facilitate?
The capture of extracellular particles.
What is Clathrin attached by?
Adaptic protein complexes - AP1) and AP2
What are characteristics of the clathrin structure?
3 legs (proximal, distal and N-terminus) with 1 heavy chain and 1 light chain per leg.
