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Flashcards in Membrane Transport and Disease Deck (47)
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1

Simple diffusion

Small gases, water, lipophilic molecules
No transporters and no specificity

2

Facilitated diffusion

Specificity
Requires transporter
Saturation kinetics observed
No direct Energy

3

Ligate gated channels respond

Signaling molecule

4

Open channels respond to

Local concnetrations of solutes

5

Voltage-gated channels respond to

Membrane potential changes

6

Channels responding to covalent modification typically

Phosphorylation

7

Mechanosensitive channels respond to

Deformations in bilayer

8

Aquaporins role, location, regulation

Water translocation
Differnet tissues
Exo/endocytosis

9

Aquaporins exampel of

Mechano-sensitive channel

10

Aquaporin sturcture

Alpha-helical homotetramers...hourglass shape

11

NDI

Nephrogenic Diabetes insipidus

12

Most common form of NDI

Defect in vasopressin receptor making kidney tubules unresponsive to vasopression (X-dominant)

13

Other form of NDA

Defect in aquaporin-2 for water reabsorption (recessive)

14

Symptoms of NDI

Large urine output, dehyration

15

F class pump

H+ across inner mitochondrial membrane

16

V class pump

H+ across endosomal/lysosomal mebrnae

17

P class pump

H+, Na+, K+, Ca2+ across plasma membrane

18

ABC class pumps

Found in plasma and intracellular membrnaes...catalyze influx of lipids, peptides, ions, and drugs

19

Primary carriers

ATp or GTP driven

20

Secondary carriers

Concentration driven

21

Importance of nuclear pore membrane wrapping

Transport of membrane proteins back into nucleus from the ER

22

Effective channel size of nuclear pore

9-26 nm

23

Fast diffuson of nuclear pore

<5 kDa

24

Slow diffusion of nuclear pore

6-50 kDa

25

Active transport of nuclear pore

>50 kDa

26

NLS

Signal for import...string of basic amino acids (+ charged)

27

NES

Hydrophobic amino acids

28

NRS

Tell to stay in the nucleus

29

Nuclear recycling mechanism

Binding of calcineurium marks NES of NF-AT and activates import signal via dephosphorylation...once back inside the nucleus, calcineurium leaves, NF-AT rephosphorylated, and NES exposed

30

What causes calcineurium to bind to NF-AT outside fo cell

High Calcium concentration