Help
Options
Didn't know it?
click below
click below
Knew it?
click below
click below
Don't Know
Remaining cards (0)
Know
retry
shuffle
restart
0:00
Embed Code - If you would like this activity on your web page, copy the script below and paste it into your web page.
Normal Size Small Size show me how
Normal Size Small Size show me how
Lecture 4: Comp Phys
Comparative Physiology USD Fall 2018 Dr. Kenneth Renner
| Question | Answer |
|---|---|
| All cells have a _________ __________ across the membrane. | resting potential |
| What are the 4 factors that create the potential differences across a membrane? | cheical factors, membrane properties, electrical factors, and ionic pumps |
| How does chemical factors play a role in membrane potential? | concentration differences in ions across the membrane creates concentration gradients |
| How do membrane properties play a role in membrane potential? | the semi-permeability of membranes allows specific substances across the membrane, but not others |
| How does electrical factors play a role in membrane potential? | ions have different charges and create electrical gradients across membranes |
| How do ionic pumps play a role in membrane potential? | ionic pumps redistribute ions and charge across the membrane to keep gradients from degrading |
| Define: diffusion | the net movement of molecules from a region of high concentration to a region of low concentration |
| Diffusion is a random _______ derived movement until solute is evenly distributed | thermally |
| once even distribution is reached, net movement is ______. | zero |
| larger molecules will move _________ and meet _______ resistance. | slower, more |
| Define: permeability | how easily a solute can cross the membrane |
| How could someone increase the diffusion across a membrane? | increase permeability, increase the area of the membrane, decrease the thickness |
| What are the five factors that net diffusion depend on? | 1. difference in solute concentration 2. permeability 3. thickness of the membrane 4. area of the membrane 5. molecular weight |
| What is the equation for diffusion? | Q=DELTAC*P*A/MW* DELTA X |
| What is the driving force for diffusion? | concentration gradient |
| Define: osmosis | diffusion of water across a semi-permeable membrane along it's concentration gradient |
| The presence of solutes _______ the concentration of water. | decreases |
| What drives osmosis? | hydrostatic and osmotic pressure |
| When does an osmotic system reach equilibrium? | when hydrostatic pressure counteracts the osmotic pressure |
| Define: Tonicity | relationship between solute concentrations between compartments |
| Nonelectrolytes such as glucose _______ dissociate. | do not |
| Define: isotonic | same concentrations inside and outside the cell |
| Define: hypotonic | less solute inside the cell (more water) |
| Define: hypertonic | more solute inside the cell (less water) |
| What are 4 key membrane properties of a cell? | 1. channels for K+ diffusion 2. minimal Na+ diffusion 3. impermeable to proteins 4. unequal ion distribution |
| The inside of the cell is typically _____. | negative |
| The outside of the cell is typically ____. | positive |
| How do ions move across the cell? | through specialized protein channels that are selective for a given ion |
| What equation derives the equilibrium potential of an ion that is unequally distributed across a semipermeable membrane in relation to electrical and chemical forces? | ZFE=-2.3RTlog[ci/co] |
| What component of the equilibrium equation is the elctrical force? | ZFE |
| What component of the equilibrium equation is the chemical forces | 2.3RTlog[ci/co] |
| What is the nerst equation | E=61mV/z(logco/ci) |
| What does the Na-K pump maintain? | ion gradiants |
| Na-K pump functions by ______ transport. | active |
| Na-K pump operates ______ [gradients] | against |
| Na=K pumps are ______. | selective |
| What can pumps be blocked by? | specific inhibitors |
| What are membrane proteins composed of? | 2 subunits |
| What is the alpha subunit of membrane proteins? | catalytic subunit |
| what is th beta subunit of membrane proteins? | glycoprotein |
| What happens in the presence of Na+ ? | ATP binds to the catalytic subunit and the Na+ binds to the catalytic protein |
| What happens after Na+ binds to the catalytic protein? | ATP is hydolyzed to ADP which induces a conformational change. |
| What happens after ADP is hydrolyzed and the conformational change is induced? | Na+ is transported outward with a Mg2+ cofactor |
| What happens in the presence of K+? | Pi is released from the catalytic subunit |
| What happens after Pi is released form the catalytic subunit? | K+ is transported inward as the protein returns to it's original conformation |
| What is the net exchange of charges in the Na-K pump? | +1 charge from inside |
| for every ___ K+ in, __ Na+ out. | 2, 3 |
| define: electrogenic | unequal idstribution of charge transported |
| What is oubain? | competitive inhibitor of the k+ binding site |
Created by:
kenzigustafson
Popular Biology sets