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Homeostasis and Transport
Wacker lecture 1/18/11
56
Physiology
Undergraduate 4
01/23/2011

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Cards

Term
blood gasses, ion conc/water, blood pressure, hormones
Definition
homeostasis regulates 4 things
Term
childbirth, thrombin
Definition
two examples of positive feedback
Term
distance
Definition
diffusion of fluid to interstitial space depends on _____ thus capillaries must be nearby
Term
concentration or charge
Definition
diffusion depends on a _____ or ______ difference
Term
142 mEq/L outside, and 10 inside
Definition
concentration of sodium outside the cell and inside
Term
outside 4 mEq/L, inside 140
Definition
Concentration of K+ inside/outside cell
Term
outside 2.4 mEq/L, insidee 0.0001
Definition
concentration of calcium inside/outside cell
Term
103 mEq/L outside, 4 inside
Definition
concentration of Cl- inside and outside cell
Term
nucleus, because they diffuse easily through the membrane
Definition
location of lipid/steroid receptors
Term
channels
Definition
ions and water must go through the membrane via
Term
plasma membrane
Definition
where are receptors for charged molecules?
Term
voltage gating & chemical gating
Definition
how are gated channels gated (2 ways)
Term
changes in the membrane potential cause a conformational change in the protein gate
Definition
how does voltage gating work?
Term
some protein channel gates are opened by binding of another molecule with the protein (causing conf change to open/close the gate)
Definition
how does chemical gating work?
Term
acetylcholine channel
Definition
whats one of the most important examples of chemical gating?
Term
it is the voltage sensor
Definition
what is significant about the 4th transmembrane loop of a voltage gated channel?
Term
part of a voltage gated channel that changes the selectivity/specificity
Definition
what is a pore loop
Term
2
Definition
how many gates are on the sodium channel?
Term
sodium and potassium channels
Definition
what are the 2 examples of volage gated ion channels?
Term
-90mV, activation gate closed, inactivation gate open
Definition
when the sodium channel is resting, what is the voltage, and what is the gate doing?
Term
-90mV - +35mV, both gates are open
Definition
when is the sodium channel activated, and what gates are open?
Term
+35 to -90mV, the inactivation gate is closed , activation gate still open(to re-activate the gates switch)
Definition
when is the sodium channel inactivated, and what gates are open?
Term
it has an inactivation gate
Definition
why does the sodium channel open/close faster than the K+ channel
Term
receptor operated, and G-protein linked channels
Definition
what are the 2 types of chemical gated channels?
Term
acetylcholine nicotinic receptor, the channel must bind 2 acetylcholine molecules to open, sodium flows through (K+ can too) seratonin type 3 receptor
Definition
what is the example of receptor operated ion channels (describe it)
Term
acetylcholine nicotinic receptor
Definition
what is an example of an ionotropic receptor?
Term
cardiac acetylcholine muscarinic receptor
Definition
example of g protein linked ion channel with chemical gating
Term
potassium, the inside of the cell is made more negative because potassium flows out
Definition
what flows through the cardiac acetylcholine....channel, and what happens
Term
beta and gamma subunit of the g protein
Definition
what opens the cardiac acetylcholine... channel?
Term
the cardiac acetylcholine muscarinic receptor
Definition
what is the example given of a metabotropic receptor?
Term
DAG activates protein kinase C, then stuff gets phosphorylated
Definition
what is the 2nd example of G protein linked channels, and how does it work
Term
ionotropic-metabo has to go through a long signaling path to change the metabolism
Definition
which receptor is faster? ionotropic or metabotropic?
Term
glut1 glucose transporter
Definition
what is the example of carrier mediated diffusion?
Term
Glut 1
Definition
what transporter is sensitized in diabetes?
Term
d = p * a (diffusion = permeability * total area of membrane)
Definition
what is the equation for diffusion coefficient?
Term
thickness of membrane, lipid solubility of compound, water solubility of compound, temperature, molecular weight (how many holes/channels in membrane)
Definition
what affects membrane permeability (5 things)
Term
diffusion coefficient, membrane permeability, concentration difference, electrical potential, pressure
Definition
what 5 things affect the net rate of simple diffusion?
Term
facillitated diffusion, its the maximum rate of diffusion determined by the concentration of carrier molecules and rate of movement of carrier molecules across the channel ex: glut 1 or glut 4
Definition
what has Vmax? why?
Term
movement of molecules against a concentration gradient. all forms require E and a carrier protein, yes has Vmax
Definition
what is active transport? does it show a vmax?
Term
primary active transport
Definition
source of energy is ATP breakdown directly
Term
Na/K+ pump
Definition
what is the main example of primary active transport?
Term
since 2 K+ go in the cell and 3Na go out (both against their gradients), there is a net negative charge in the cell.
Definition
what is the charge result of the Na/K+ pump?
Term
Na/K+ pump
Definition
what maintains osmotic pressure
Term
inhibit the Na/K+ pump, important in excitability of cardiac myocyte membrane
Definition
what do digoxin and oubain do?
Term
secondary active transport
Definition
uses energy of one solute moving with the concentration gradient(created with primary active transport earlier) to move another substance against the concentration gradient
Term
cotransporters
Definition
symport, both ions in the same direction one "uphill" one "downhill"
Term
exchangers/coutertrasport
Definition
antiport, ions move in separate directions (one uphill and one downhill)
Term
sodium
Definition
what molecule do secondary active transport pumps usually use?
Term
sodium/aminoacid transporter, sodium/phosphate transporter
Definition
what are the 2 examples of cotransport?
Term
sodium calcium 3:1, and sodium hydrogen 1:1
Definition
what are the examples of countertransport exchangers?
Term
4 unit proteins called aquaporins
Definition
how does water move into a cell?
Term
osmosis
Definition
solvent moving from area of high solvent concentration to low
Term
semipermeable membrane, concentration of solute(osmolarity) determines movement
Definition
membrane where water can move, ions cannot, how is movement determined?
Term
hypertonic
Definition
higher osmolarity
Term
hypotonic
Definition
lower osmolarity
Term
isotonic
Definition
same osmolarity
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