Cell Dynamics Anderson Flashcards
examples of integral proteins (anchored, span entire membrane)
ion channels and transport proteins
example of peripheral proteins
hormone receptors
why is potassium a main intracellular ion?
because the Na/K pump sends 3 NA out and brings 2 K in
glucose is cotransported with
Na
type of transporter that requires ATP
active…can transport against the gradient
type of transporters that are substrate specific
facilitated and active
while most substances that pass through the cell membrane are via diffusion and active transport, those that are too large require
endocytosis which requires ATP…pinocytosis is engulfing small things and phagocytosis is engulfing large things
channels can be gated in these two ways
voltage (membrane potential) or ligand (hormone, 2nd messenger)
major ICF ions
K, Mg
major ECF ions
Na, Ca, Cl
explain action potential sequence
-70 at rest, Na+ gates open and Na+ floods into the cell, then K gates open, sodium gates close, and K gates slowly close which leads to hyperpolarization
what is depolarization
makes the membrane potential less negative (cell interior)
hyperpolarization
makes membrane potential more negative (interior)
outward current
flow of positive charge out of the cell which hyperpolarizes the membrane potential
action potentials are
all or none
threshold is
the membrane potential at which the action potential is inevitable
where is the synthesis of a small neurotransmitter (Dopa, NE, Epi, GABA, Glycine, Glutamate, Serotonin)
cytosol of the presynaptic terminal
where is the synthesis of a neuropeptide neurotransmitter (ACTH, TSH, etc)
in the neuronal cell body, by the ribosomes
how are small molecule neurotransmitters released
stored in vesicles and release triggered by AP at presynaptic membrane…removal is recycling back into presynaptic membrane
how are neuropeptide neurotransmitters released
golgi packages into transmitter vesicles that are released into axonal cytoplasm, release triggered by AP…neuropeptides are autolyzed and not recycled
2 classes of cholinergic receptors
nicotinic and muscarinic
where are muscarinic receptors
postsynaptic parasympathetic, sweat glands…use second messenger
where are nicotinic receptors
autonomic ganglia, sympathetic and parasympathetic ganglia, adrenal medulla, neuromuscular junction…ligand gated
4 types of adrenergic (NE/Epi) receptors
alpha 1, alpha 2, beta 1, beta 2…alpha are excitatory except in GI and beta are inhibitory except in the heart
