Week 1 Day 2 Membrane transport, Osmosis, Cell signaling Flashcards
What are the 3 types of passive diffusion? What are their definitions?
- Simple diffusion: Molecules diffuse from a greater concentration to a lower concentration (estrogen)
- Active diffusion: Molecules diffuse from a lower concentration to a higher concentration (e.g. NA+)
- Diffusion via transporters: Diffuse via membrane proteins (e.g. glucose)
What gradient will molecules always flow when going through channels?
-The concentration always moves down concentration gradient
What are the 3 types of gated channels? Brief description of each?
- Voltage-gated ion channel: Stimulated by voltage
- Ligand-gated ion channel: Chemically gated
- Mechanically gated ion channel: Mechanic force required
When are transporters required to be used?
When there are large polar molecules to diffuse or active transport
What changes about the transporters when it shuttles solutes through it?
The transporter will squeeze/shuttle molecules through it and go through conformational changes.
What are the two types of transporters?
-Active and passive transport
What are passive transporters called? And, what type of port does it have?
- Another name for passive transport is facilitated diffusion
- It has a uniport, which means it’s moving in one direction
What are the two types of active transport?
-Primary active transport & secondary active transport
What type of port does a primary active transport have?
It has a uniport (moving in one direction)
What are the two types of port that a secondary active transport has?
- Antiport (moving in both directions/opposite)
- Symport (gradients move in same direction)
What are the 3 characteristics an active transporter has?
Specificity, competition, saturation
In drawings, what color does green indicate?
-Facilitated diffusion
In drawings, what will the color red indicate?
Red will mean active transport.
What does specificity mean as it pertains to transporters?
-How specific the transporter protein is
What does competition mean as it pertains to transporters?
The more specific, the more competitive the transporter protein is
What does saturation mean as it pertains to transporter characteristics?
When all the proteins are fully saturated with ligands
What is the example Angela used to display competitive active transporters?
tamoxifen, which binds to the hER alpha and hER beta receptor
What type of energy does primary active transport use?
It uses ATP
Waht type of energy does secondary active transport use? And where does it get its energy from?
- Uses an electrochemical gradient
- requires energy from primary active transport to initiate
What type of active transport is the NA/K pump? Does active transporters bring cells to equilibrium or disequilibrium?
-primary active transport.
For NA/K pump, describe the movement of sodium and potassium
3 NA+ go out of the cell and 2 K+ go in
If a membrane is permeable, what does it let in and how does it effect net change in volume?
If it is permeable, it lets in lipophilic/non polar molecules are there is no net change in volume
If a membrane is selectively permeable, what does it let in and how does it effect net change in volume?
If it is selectively permeable, it lets in lipophobic/polar molecules and the net water mvt be different
What is the definition of molarity?
Number of molecules in a solution
What is the definition of osmolarity?
Number of particles in a solution