| Flap 1 |
Flap 2 |
| True or False, the body is electically neutral? | True |
| True or False, all cells of the body have an electrical potential across their membrane? | True |
| What units are electrical potential measured in? | Volts or millivolts (in Biological systems) |
| What is current? | The flow of electons |
| True or False, the movement of a positive ion from one side of a membrane to the other implies a negative charge is left behind? | True |
| What is Ohm's Law? | I (currrent flow) = E (electrical potential) / R (resistance) |
| True or False, the lipid membrane has low electrical resistance thus, making it a good insulator? | False the lipid membrane has a high electrical resistance |
| True or False, The extracellular fluid and intracellular fluid both have low electrical resistance? | True |
| What is the conventional voltage outside the cell? | 0 |
| What are the 2 types of ion channels? | 1. Leak channels - open all the time 2. Na/K ATPase Pump - electrogenic pump making the ICF more negative |
| What ions pass through leak channels? | 1. Na 2. K 3. Cl |
| True or False, The membrane is 75 times more permeable to K than Na? | True |
| True or False, the Na/K ATPase pump account for only 5% of the resting membrane potential? | True, leak channels account for the remaining 95% |
| What are the 2 forms of gradients? | Electrical and Chemical |
| Together the two types of gradients form what? | The Electrochemical gradient |
| Inside the cell is relatively ________ compared to the outside of the cell? | Negative |
| What is the usual range for the membrane potential? | -40 to -90 millivolts |
| A cell with a resting membrane potential is said to be polarized or depolarized? | polarized |
| True or False, Both the inside of the cell and the inside of the cell are electrically neutral? | True |
| What factors determine membrane potential? | Membrane Permeability, Leak Channels, Na/K ATPase Pump, and difference in Ion concentrations |
| How many Na+ ions ar inside the cell? outside? | Inside 14, outside 140 |
| How many K+ ions ar inside the cell? outside? | Inside 140, outside 4 |
| How many Cl- ions ar inside the cell? outside? | Inside 4, outside 108 |
| What ion helps balance Na+ in the ECF? | Cl- |
| What helps balance K+ in the ICF? | negativley charged proteins |
| True or False, The membrane is freely permeable to Cl-? | True |
| True or False, Na moves down its concentration gradient more easily and faster than Na+? | False, remember the membrane is 75 times more permeable to K+ |
| True or false, the Ion flux would = 0 if 1 Na was pumped out and 1 K was pumped in? | True |
| Describe the Nernst Potential? | The Nernst Potential is the equilibrium potential for any ion across the biological membrane |
| What is the Nernst Equation? | Equilibrium of (X) = R(Gas Constant)T(temp.) / Z(charge or valence)F(farady's constant) log [X] inside / [X] outside |
| What is the easy way to calculate the nernst potential? | Equilibrium of [X] = -61mV log [X] / [X] outside. |
| Can proteins move in and out of the cell without help? | No. |
| What is the equation fo the net current flow (I) across a membrane? | I[X] = g[X] (ion conductance) {Em(resting membrane potential) - E[X](Nernst Potential) |
| True or False, when the resting membrane potential is not changing, then the sum of all currents must equal zero. | True |
| What are the 2 forms of electrochemical signals? | 1. Graded Potentials = Short distance 2. Action Potentials = long distance |
| What is the jist of the Goldman Equation? | Basically the resting membrane potential is a sum of all the ion potential times their percentage of the total ion concetration. |
