Reading...
Play button
Play button
Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
28 Cards in this Set
- Front
- Back
|
What are the 3 types of movement?
|
1. Bulk Flow
2. Diffusion 3. Transport |
|
|
What are some examples of Bulk Flow?
|
*CONVENTION*
1. blood/artery 2. air/bronchiole 3.chyme/intestine |
|
|
What are some examples of Diffuision?
|
*WITHIN COMPARTMENTS*
1. passive/random thermal action 2. concentration gradients |
|
|
What are some examples of Transport?
|
*ACROSS BARRIER*
1. solubility + Diffusion/ lipid bilayer 2. Carrier mediated transport 3. Endo/Exo-cytosis |
|
|
What does FICK'S LAW of diffusion depend on?
|
1. Concentration gradient
2. Area |
|
|
Why are cells no further than 100um from thier energy source?
|
Distances greater than 100um increase the time of diffusion by a lot!
|
|
|
Why are cells no bigger than 10um?
|
Because a cell that is greater in size will be less efficient in moving things around the cell..by ALOT!
|
|
|
So what do diffusional distances tell us about the function?
|
If we need diffusion to be slow then distances should be greater like in dermis which provide a protection function vs. a mitcondria that has small distance across b/c it needs to produce energy fast!
|
|
|
What does the partition coefficient tell us?
|
measure of a solute lipophilicity and an indication of its ability to cross cell membranes.
|
|
|
What does a Partition coefficient greater than 1 tell us (1>K)?
|
Lipophilic i.e can cross easily across lipid bilayer
|
|
|
What does a Partition coefficient Less than 1 tell us (1<K)?
|
Lipophobic i.e cannot cross easily acoss lipid bilayer
|
|
|
What can DIFFUSE across the lipid bilayer?
|
1. Gases
2. Small,uncharged, POLAR molecules (ethanol) |
|
|
What can DIFFUSE across the lipid bilayer very little?
|
1. Water
2. UREA |
|
|
Why does Asprin get absorbed in the stomach quickly?
|
1. pKa of aspirin is low
2. pH of stomach is low =therefore, Asprin in stomach exist as non ionized form and is able to diffuse through lipid layer |
|
|
Why do you get drunk faster w/alcohol when you dont eat?
|
1. The Deudunem has a huge surface area w/huge absorption potential
2.food breakdown slows digestion and therefore, maintains alcohol in stomach longer where surface area for absorption is smaller |
|
|
Do glucose, adenosine, urea, alanine diffuse through lipd membrane?
|
No, these molecules are TRANSPORTED by membrane proteins b/c they are essential for energy
|
|
|
Which membrane transit pathway has the highest selectivity for its substrate?
|
Ion channels<pumps/transporters
|
|
|
Does each monomer of a homotetramer aquaporin conduct water?
|
Yes
|
|
|
How many pores exist in a homotetramer aquaporin?
|
5
|
|
|
Which aquaporins also transport glycerol and urea?
|
AQP:
3(epithelial basolateral membrane), 7(proximal tuble), 9 (epithelial basolateral membrane), 10(small intestine) |
|
|
Are these poisons, vinblastin and vincristine transported across the lipid bilayer?
|
yes
|
|
|
During SECONDARY ACTIVE TRANSPORT glucose taps into the sodium gradient energy gradient. Does water follow sodium?
|
Yes
|
|
|
What is an example of a Transporter?
|
Glucose comes in
|
|
|
What is an example of a Cotransporter
|
Na+ and glucose come in together
|
|
|
What is an example of an Exchanger
|
Na+ in
H+ out |
|
|
Which have higher specificities: transporters/pumps or channels?
|
Transporters and pumps since they require molecular conformation
|
|
|
Which pass more stuff through them per second: transporters/pumps or channels?
|
channels: millions per second
|
|
|
Which are saturable: transporters/pumps or channels?
|
transporters and pumps
|
