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Phys Lect 2
Question | Answer |
---|---|
Key functions of Cell Membrane | Keeps essential cell proteins within the cell. Also, b/c it is selectively permeable, it allows for movement of: 1.substrates. 2.metabolites (ex: glucose). 3.signaling molecules (ex: Ca2+). |
Main requirement of BULK FLOW molecule movement? | Driving pressure. **EX: Inpiration: expansion of the lungs causes a lower pressure within the lungs than outside, therefore the driving pressure moves air from the atmosphere into the lungs |
Factors effecting rate of diffusion | 1.Concentration gradient. 2.Area available for diffusion (More A = Inc rate). 3.Permeability Coefficient (lipid solubility: size and charge) |
On a diffusion Rate graph, a line with the same concentration gradient will have a lower slope if: | The Permeability coefficient or the Area of diffusion is lowered. |
Is Facilitated diffusion Saturable? | YES. Once all proteins are occupied, the rate of diffusion will no longer increase no matter the concentration increase. |
One method of controlling ion movement across membranes | Ligand or Voltage gated channels. |
3 main ways molecules move in physiological systems | 1.Simple diffusion. 2.Facilitated diffusion (requires a membrane-bound protein channel/gate). 3.Active Transport. |
Graphical depiction for simple diffusion? | Linearly increasing |
Graphical depiction for facilitated diffusion? | Increases until a certain point and then levels off b/c all the protein channels are occupied: SATURATED |
What is secondary active transport? | ATP is NOT directly used: the movement of one molecule across its [con] gradient via symporter or antiporter. **It uses the displacement of the molecules from the Na/K ATPase to drive the symporter/antiporter. |
How do Cl- and H+ reach the stomach lumen from the parietal cell? | 1.Cl- comes enters parietal cell via chlorid-bicarbonate antiporter (secondary active transport) and then enters the stomach lumen via Cl- channel (facilitated diffusion). 2.H+ is exported into the stomach lumen through a H+/K+ ATPase (Active transport) |
What does Omeprazole do? | Inhibits H+/K+ ATPase causing a decrease in stomach acid production. **Treats HEART BURN** |