Cell of ions Flashcards
Learn
Diff between solvent and solute
Solute are particles dissolved in solvent. Solvent is the fluid present.
What are the 4 fluid compartments of the body?
Plasma (NA+ Based)
Interstitial (-Plasma, lacks blood proteins(anions))
Intracellular (K+ based and lots of anions)
Transcellular (In lumen of tubes/organs e.g. spinal fluid, chyme in GI)
Difference of diffusion and osmosis
Diffusion the movement of solute molecules down conc gradient
Movement of solute down conc gradient
5 important e.g. of cations and anions
Cation: Na,K,H,Mg2+ Ca2+
Anion: OH, Cl, HCO3, SO4, PO4
Where are ions found? give 6 examples
Eggs cuffed in jail together buffering their teeth
Free in solution, tightly bound, sequestered, chelated, buffered, teeth/bones
5 ways ions cross the membrane
channels, co-transporters, exchangers, pumps, leaks.
9 things ions do
Start cellular process Act as chemical messengers Fertilisation Muscular contraction Exocytosis Control transmembrane voltage Move water via the kidneys Activate enzymes Create energy as ATP
5 things that happen if ion conc is wrong
Heart, face, brain, bones, skin Cardiac arrhythmias Tics/nervous dysfunction Seizures Bone deformities Oedema
9 things that cause ionic imbalance
Trauma/hemorrhage Diabetes Diruectics Kidney dysfunction hormonal imbalance Dehydration vitamin d imbalances Poisons D&V
Conductance equation?
I = g x V or g = I/V
What is the membrane potential (Vm) and the membrane potential (RMP)
Vm= voltage across the membrane, this indicates real voltage and change during an AP RMP= An ideal set point
What is the difference betweeen chemical and electrical force
Chemical force is based on conc diff across a membrane e.g. 10x Na out then in then 60mv directed into cell
Electrical = based on the Vm and having unpaired +ve charge with -ve charge on one side of the membrane
What is equilibrium of chemical and electrical force?
What is the equation of net force?
Chemical force = -1x electrical force:
net force = 0
Net force = chemical + electrical force
Is Potassium and Sodium higher intracellular or extracellular?
Potassium higher inside
Sodium higher outside
What is the diff between excitable and non-excitable tissues? give examples.
Excitable: able to propegate an AP e.g. muscle and neurons
Non-excitable: cells w/o an AP e.g. epithelial, skin, liver
Describe the differences between body fluids composition of Plasma, Intracellular fluid and extracellular space.
plasma: Highest in Na to balance protein anions, slightly negative than ECF
ICF: Highest cations, highest proteins, higher elctrolyte conc, most negative voltage
Extracellular space:
Highest Cl conc(lacks protein anions)
lowest elctrolyte conc
Describe the 4 places where calcium can be found
Free Calcium, ionized and in solution (free to activate enzymes)
Bones, insoluble solid will not react w enzymes
Bound to proteins will not react
Sequestered in cellular organelles e.g. sarcoplasmic reticulum
What does free Ca do? and explain the differnece between inside and outside the cell
Free Ca is 10,000x more outside the cell than inside.
Enzymes and proteins are activated when IC free Ca is increased causing changes such as muscle contraction
What are the 3 rules of ionic balance
- Conc of +/- ions must nearly balance
- Ions leave cell must be replaced by the same ion
- Energy is used to re-establish ion gradients across membranes
Carbonic anhydrase is used to
Create acid/base
Indirectly helps H+ cross membranes
Indirectly helps CO2 transport around the body
Cl shift to remove H+ from muscle in RBC
Eliminating CO2 in lungs
Secreting HCl in gastric parietal cells into the stomach
Secreting bicarbonate in the pancreas
What it the carbonic anhydrase catalyst reaction?
CO2+ H2O -> H2CO3 -> H+ + HCO3-
Name the process of the gastric parietal cells moving ions in 4 steps.
- Pumps H/K against conc gradient creates acidic space outside. Bicarb inside the cell out to blood and diluted to co2 then breathed out.
- K channels open and k moves via conc gradient out cell. Cl- moves out with H to pump out HCl. Cl moves down conc gradient.
- Cl- channels open and cl moves passively to get rid of extra cl. K channels balance charge.
- NaK pump maintains intracellular K conc.
