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Flashcards in bcm33 Deck (12):
1

most important determinants to get through membrane

polarity
charge
concentration gradeitn

2

3 ways to cross membrane

1. passive diffusion down ec conc grad
2. faciliated d down ec conc grad
3. at against conc grad
- primary = light energy
-seconadary trade one gradient for another

3

example of faciliated diffusion

ionophores
ion channels
porins
K+ channel vita for gen resting potential

4

what is patch clamping

study transport through membrane
thin quarts glass pippettte with blunt end sealed onto membrane suction applied to seal tight
pore isolated all ions flow into pippete
recorded by silver chloride electrode sensitive amplifier

5

ficks law

diffusion of a chemical occurs in the direction that eliminates its concentration gradient at a rate proportional to the magnitude of this gradient.
j= d [a] out -[a]in / x
j= influx/sec/unit area
d= diffusivity coefficient for a, viscoity of membrane, oil solubility
x= membrane thickness

6

osmosis

facilitated diffusion through aquaporins
mutation of aqua porin 2 causes rare form of diabetes insipidus.

7

what kinetics does fd show?

saturation kinetics
transporters= enzymes

8

ionophores

small non protein molecules that mediate diffusion
eg. valinomycin
antibiotic carries 10^5 K+ accross membrane

9

concentration of ions in blood

K+ is much lower
Na+ is much higher
Cl- is much higher
Ca2+ is much higher

10

uni port
- mechanism
- example

1 way, 1 ion
calcium p type atpase
restores ca2+ gradient accross sarcoplasmic reticulum

11

antiport
mechanism
example

2 ions opposite directions
Na+/K+ type Atpase
maintain resting potential of mammal cells

12

symport
mechanism
example

2 ions same direction
glucose Na+
move glucose into intestine