1.
**ABC1 subfamily what does it transport: cholesterol and phospholipids out of macrophages
2.
2 examples of countertransport/anti port: only secondary active
Na - Ca exchanger
3 Na enter/ 1 ca exchanged therefore electrogenic exchanger
Also Na H exchanger pumps H from cell in response to falling pH
3.
are all the muscle fibers in a motor unit of the same type?: yes, small motor units are small diamater axons and contain slow oxidative fibers
4.
associated with some forms of muscular dystrophy: titin, titin connects z line to myosin
elastic properties of muscle, allows muscle to recover, also can be a mechanoreceptor that participates in mechanical activity dependent gene regulation and protein degredation if messed up = dystrophy
5.
can smooth muscles undergo greater degree of shortening than skeletal msucles: yes
6.
Describe both ends of the reflection coefficient: 0 = molecule is as permeable as H20 (extremely permeable)
1 = solute is completely impermeant
7.
Describe standing gradient osmosis: Na+ actively pumped to lateral intercellular spaces; electrical potential created by Na+ transport draws Cl- (and HCO3-) into extra cellular space; solution in lateral intercellular space now hyperosmotic;osmotic flow of H20 into there from lumen and surrounding cells ; hydrostatic pressure pushes solution out of intercellular space; reaches serosal border and is nearly isotonic.
8.
Describe the paracellular pathway of transport: occurs across epithelial layer. substance moves BETWEEN epithelial cells through tight junctions and into lateral intracellular space. (skips apical, cyto, basolateral)
Mechanism: Ions or H20 are doing the moving in response to a) electrical or chemical gradients (ions) b) osmotic gradients (H20) NOTE osmotic differences are the only forces controlling movement of H20; there are no "H20 pumps"
9.
Describe transcellular pathway of transport: occurs across epithelial layer. Substance goes across apical and basolateral membrane. mechanism: a substance is ACTIVELY transported across ONE layer and leaves the OTHER LAYER by a passive process (DIFFUSION OR FACIL. TRANS)
10.
do receptor regulated Ca channels in smooth muscle create depolarization?: no
11.
does smooth muscle have creatine phosphate?: no thats why it the relaxation cycle is slow, well part of the reason
12.
Example of H transport besides Ca H antiporter: ATPase H+ / K+ ; transports H+ into gastric lumen and K into parietal cell
13.
examples of cotransport aka symport: only secondary active
Na cotransport of AA
Na cotransport of glucose (intestine only)
Na-K-2Cl co transporter
14.
Examples of specificity and not absolute specificity in glucose transporters: stereospecific D> L
yet transports other sugars
15.
examples of uniporter: facilitated diffusion of glucose
16.
Explain glucose transport (in small intestine): Secondary active transport @ luminal border. Na+ out , Glucose in. leaves basolateral cell membrane via fac. diff.
17.
Fick equation (diffusion) for continuous and discontinuous: J = -DAc
c = concentration gradient dc/dx
J = -DAC/X
C= delta concentration gradient
X = thickness of barrier delta
18.
glucose transport across skeletal cells is an example of what? Across intestinal epithelia?: facilitated diffusion
intestine: secondary active, cotransport of glucose (Na)
19.
H band: composed of just myosin (changes length w/ contraction)
20.
How can ions move across membrane?: only by intrinsic membrane proteins (channels, pores, transporters)
21.
how can MLCK be phosphorylyzed (inactivated/ relaxation): MLCK can be phosphorylyzed in vascular/bronchiolar smooth muscle at B2 receptor to activate CAMP which activates PKA which phosphorylyzes MLCK
2- NO increases cGMP levels and activates protein kinase G which phosphorylyzes MLCK
22.
how do you get greater tension w/ phosphorylation in smooth muscle?: phospholipase c is activated to cleave phosphatidil iositol to produce Ip3 and DAG. Ip3 induces Ca2+ release, while DAG phosphorylates MLC phosphatase inhibiting it and resulting in greater tension
23.
how does Ca get out of myplasm in smooth muscle?: Sarcolemma pathway:
1) Ca pump
2) Na - Ca exchanger ( 1 ca out for 3 Na in)
SR pathway
a) Ca pumps on SR membrane pump Ca 2+ into cell
b) SR contains Ca binding proteins calreticulin in addition to calsequestrin
24.
how does PMCA work?: inactive at physiological [Ca] as [Ca] rises combines with calmodulin. CaM combines w/ PMCA and increases the pump's affinity for Ca2+
[Ca2+] levels fall and cAm dissociates inactivating pump
25.
how is action potential activity governed in neuron?: sum of all synpatic inputs , inputs closer to trigger zone have greater influence. (because of decremental conduction on way to trigger zone)
only membrane potential at trigger zone is important to trigger action potentials since this is where they originate from
26.
If you have movment of a solute much faster than what can be accounted for by diffusion what is a possible explanation besides transporters: bulk flow
27.
IPSP: transient hyperpolarization sometimes but not always produced. important point is that inhibitory transmitters drive membrane potential to a level more negative than threshold
28.
K+ secretion: If there are K channels on the apical membrane (as there are Na channels) then some of the K taken up in basolateral membrane by the K/Na transporter will head to the lumen. This is mechanism used by collecting tubule of kidney to secrete K+
29.
M line: is in the middle of myosin filaments
30.
molar weight of water: 55.5 molar
31.
multiunit smooth muscle: few gap junctions, finer control, no spontaneous contractile activity, no action potentials***
32.
Na + absorbtion: Na/K pump in basolateral membrane shoots out Na+ keeping gradient of more outside than inside. Results in a net POSTIVE charge in lumen to interstitum (cause you are putting more + in interstitum from basolateral mem ). Cl - migrates via paracellular pathway from lumen to interstitum. NET RESULT = NaCl collected in collecting tubule of kidney.
33.
Na/K pump is located exclusively on which membrane? What is the one exception?: basolateral membrane, exception is choroid plexus.
34.
nebulin: goes from z line to end of actin filaments , regulates precise length of each thin filament
35.
osmolarity, osmolality: osmolarity: moles/ L
osmolality: mols/ Kg of H20
36.
plasma osmolarity: 300 mosmoles/ L
millimoles
37.
The movment of H20 occurs across a cell membrane from a region of ___ osmotic pressure to a region of ___ osmotic pressure.: low, high. Remember osmotic pressure is the force needed to balance water from entering area. Therefore high osmotic pressure = high solute concentration. Water goes from low solute concentration to high (i.e. low osmotic pressure to high)
38.
thin to thick ratio in smooth: more thin to thick than skeletal many thin surround just a few thick
39.
ultrafiltration seperates what: small particles and H20 from proteins and cells which stay in the blood
40.
units for diffusion equations: cm^2/sec
41.
What are MDR subfamily of ABC transporters found in?: liver, kidney, GI tract
42.
what do axonaxonic synapses allow for?: both inhibition and facilitation of transmitter release
43.
what do net osmotic H20 flow, and osmotic pressure, approach as reflection coefficient of particles in a solution approach 0: 0
44.
What do SERCA and PMCA exchange for the Ca: Hydrogen
45.
what do thin filaments anchor into in smooth muscle: dense bodies
46.
What is an example of facilitated diffusion?: Glucose transport across skeletal cells
47.
what is are teh two things that can trigger malignant hyperthermia: halo thane and succinyl choline; produced by abnormality in ryanodine receptor causing excessive Ca2+ loss from SR.
48.
what is EPSP: excitatory post synaptic potential
is a transient depolarization released from excitatory transmitter action
49.
What is fick's first law across a permeable membrane (membrane is something that ions interact w/ ): J = - ABCD/ delta X
A= area of diffusion
B = partition coefficent
C = concentration (inside - outside)
D = diffusion constant WITHIN membrane
take out stuff related to ion and membrane (DB/X)
leave area and concentration
J = - PAC
P = permeability coefficient: DB/X
D = T/(viscosity * radius of molecule)
50.
what is intracellular Ca levels at?: 0.1 uM or less
51.
What is partition coefficent?: [i] oil / [i]water
conc. of sub i in oil/ conc. of substance i in water. If = 1 then completely soluble in lipid
52.
What is the equation for osmotic pressure?: Pie = RTnc RT = 25 1atm/mole n = number of particles formed by dissociation of a solute molecule c = molar concentration of solute (moles of soulte/liter)
keep in mind that its moles not millimoles*** must convert
also gives answer in atm not mmHG must multiply by 760
53.
What is the final derivation of Fick's law for flux across a membrane?: J = - PA(Ci-Co)
54.
What is the membrane potential of a cell? Why?: -50 to -60 mV; Most K+ taken up by Na/KT transporters in the basolateral membrane leaves through K channels in the basolateral membrane, because of the abundance of these channels membrane potential is pretty much just determined by K gradient.
55.
what mediates long term potentiation?: NMDA receptors after strong tetanic stimulation. glutimate is released, activation of NMDA receptor leads to production of retrograde messenger CO or NO. to make more Ca channels in post synaptic (even tho it came from presynaptic) cellular model for memory
56.
What substances can readily pass through membrane?: gasses (O2, CO2) and small uncharged water-soluble molecules
nothing w/ MW > 200
57.
what type of contraction leads to max cross bridge cycling and how is it determined?: max velocity and determined by ATPase activity of myosin present
58.
What would adding extracellular K do to an action potential?: large concentration gradient for K. Therefore adding EC K destroys this gradient and will lead to immediate depolarization of cell. Eventually K will equilibriate and destroy gradient/membrane potentital
59.
where do action potentials originate?: axon hillock-initial segment region
60.
Where is CFTR subfamily found? How does ATP regulate CFTR?: apical membrane of many epithelial cells in GI tract , ducts of liver, pancreas, and salviary glands
regulatory domain must be phosphorylzed. cAMP is elevated, PKA is activated,.
Also 2 NBDs bind ATP for channel to function
61.
Where is Na- K - 2Cl located***: 2ndary active transporter
regulation of cell volume/ increasing Na K Cl
found in non epithelial cells nad basolateral membrane of some epithelial cells.
62.
where is ryanodine located?: SR
63.
Which bands dont change length with contraction?: a band
64.
which two bands change length w/ contraction?: H and I
