Cell Membrane And Transport Flashcards
Ficks law of diffusion
J=-DA delta c/delta x
Most important factor determining movement of lipid soluble substance across cell membrane
Lipid solubility >molecular diameter>molecular weight
Nephron transporters
UTA1 UTA2 . . UTA4
RBC and vasa recta transporter
UTB
Non-ionic diffusion of NH3 where
Collecting duct
Eg of non-ionic diffusion
Secretion of NH3 by collecting duct cells
Excretion by weak acids and weak bases by collecting duct
Absorption of weak acids by stomach
Absorption of bile acids by distal ileum
Primary active transport by
Na-k pump
H-k pump
SERCA
Secondary active transport types
Co-transport
Counter transport
Main function of Na-k pump
Genesis of RMP
Cell volume regulation
Binding site on Na-k pump on ECF side
K- binding site
Ouabain binding site
3 sites on inner side of Na-k pump
Na binding site
ATP binding site
Phosphorylation site
Affect of hormones on Na-k pump
Thyroid,aldosterone,insulin,dopamine,anp
Check book ;)
Co transport counter transport eg
Check notebook pls 🤲🏽
Eg of docking protein
Syntaxin/T-snare protein
Synaptobrevin/V-snare protein
SNAP-25
Eg of non-constitutive/regulated exocytosis
Synthesis-processing-storage-release
Eg pls check
Constitutive pathway exocytosis eg
Synthesis-release
Secretion of Ig by plasma cell
Secretion of collagen by fibroblast
Pinocytosis eg
Ca
ATP
Cadherin
Caveolin
Transcytosis eg
Colostrum to baby blood
(As intestinal epithelium is not mature in newborn
Donnan effect
When two compartments are separated by semipermeable membrane with impermeant anions (protein-) on one side of this semi-permeable membrane,there is an unequal distribution of a pair of diffusable ions at equilibrium (no net transport)
Gibbs-donnan equation
Gives the mathematical relationship between 2 diffusible ions at equilibrium in 2 compartments separated by semi-permeable membrane with impermeant anions (-pr) on one side of this semipermeable membrane
Nernst equation
To calculate equilibrium potential
Equilibrium potential=2.3 RT/FZ log c1/c2
(Know what each of those letters mean)
2.3RT/F =61.5 mV (approx 60 mV)
Equilibrium potential of K Cl Mg Na Ca
K=-90mv Cl=-70mv Mg=0mv Na=+61 mV Ca=+125 mv
Resting membrane potential given by which equation
Goldman Hodgkin Katz equation
Goldman Hodgkin Katz equation based on 2
Conc gradient of ions
Cell membrane permeability for the ions
Check the equation pls
So in the equation conc for negative charge ion on the numerator side is of outside or inside
For negative ion the outside conc is numerator
Cell membrane is most permeable to which ion at rest
K+
Most diffusible ion at rest
K+
If extracellular concentration of Na+ is increased agar happens to RMP
No Change (Membrane is almost impermeable to Na)
Which ion contribute to maximum to RMP
K+
Values of RMP of different cells
Pls pls check your mobile
Effect of hypokalemia on RMP and common symptom
Increase potential
Decreased excitability
Symptom -muscle weakness
If you don’t know how it happens pls go through your notes -.-
Effect of hyperkalemia on RMP and common symptom
Increase potential
Decrease excitability
Symptom-arrhythmia
If you don’t know how it happens pls go through your notes -.-
Two types of channels
Leak
Gated
Types of gated channels
Voltage gated
Ligand gated
Phosphorylation channel
Mechanosensitive
Dimer trimer tetramer pentamer channels
Dimer -not in humans (chloride channels in bacteria,animals)
Trimer - ENaCs (epithelial Na channel)
Tetramer - K+,acquaporin
Pentamer- chloride channel,ligand gated channel (acetylcholine receptor)
Feedback systems
Negative
Positive
Adaptive control
Negative feedback eg
Control of blood pressure with baroreceptor mechanism
Positive feedback eg (mnemonic)
C-clotting,ca release from SR during muscle contraction L- LH surge,let down reflex A-action potential P-parturition S-shock
Gain of negative feedback system formula
Correction/error
