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Flashcards in Membrane Proteins Deck (25):
1

diffusion

spontaneous movement of a substance from 1 region to another, often w/ net movement from high conc. to low conc.

2

facilitated diffusion

passive transport of a substance across a membrane w/ assistance of transmembrane carrier proteins or channel proteins

3

carrier protein

specialized membrane proteins that change shape during the transport process

4

channel protein

enable ions or polar molecules to move across lipid bilayers efficiently in response to existing gradient

5

active transport

movement of ions/molecules across membrane against an electrochemical gradient
- requires energy & assistance of transport protein
- must counteract entropy ↓

6

protein models

(1) fluid mosaic model

(2) sandwich model

7

freeze-fracture electron microscopy

innovative technique for visualizing surface of plasma membranes

8

peripheral membrane protein

protein that binds to membrane w/out passing through & a protein does not span entire lipid bilayer & associates w/ only one side of bilayer
- some only found in interior cell
- others only found on exterior cell
- often attached to transmembrane proteins
- come off easily

9

integral membrane protein

protein that spans membrane & has segments facing both interior & exterior surfaces
- hydrophobic embedded part
- some transmembrane parts

aka. transmembrane protein

10

detergent

small amphipathic molecule used to solubilize hydrophobic molecules in aq. solution

11

electrochemical gradient

combo of ion’s [] gradient & electrical (charge) gradient across a membrane that affects ion diffusion across membrane

electrical + chemical -> diffusion

12

channel proteins

types of pores in cell membrane
- enable ions / polar molecules to move across lipid bilayer in response to existing gradient
- selective: permits particular types of ions or small molecules to pass through only

13

gated channel

channel protein that opens/closes in response to specific stimulus

(ie) aquaporin & ion channel
(ie) voltage & ligand gated

14

aquaporin

type of channel protein in which water moves cross plasma membrane over 10x faster than w/out aquaporin

"water-pores"

15

ion channel

specialized protein channel that allows certain ions to diffuse across plasma membrane down an electrochemical gradient
- form pores in membrane, which is where ions move through

16

passive transport

powered by diffusion along electrochemical gradient
- no need energy
- use gradients as force

(ie) facilitated diffusion

17

secondary active transport

gradient set up by pump provides energy required to pwr movement of diff. molecule against its particular gradient
- link passive to active
- glucose movement in small intestine against [] gradient
- Na+ down gradient, glucose against gradient
- no ATP

aka. cotransport

18

pump

protein membrane that can:

(1) hydrolyze ATP

(2) change shape

(3) pwr active transport of specific ion/small molecule across plasma membrane against electrochemical gradient

- independent of gradients

19

primary active transport

critical for membrane potential

20

channel fcn

(1) passive transport

(2) facilitated diffusion

(3) electrochemical gradient

21

carrier protein fcn

(1) passive transport

(2) facilitated diffusion

(3) electrochemical gradient

22

voltage gated

charge (+/-) depends on open/close

23

ligand gated

depends on if ligand (binds to receptor) is on channel or not

24

membrane-associated proteins

(1) peripheral membrane protein

(2) integral membrane protein

(3) glycoprotein

25

glycoprotein

only present on exterior of cell or inside of golgi
- creates diff. blood types
- cell receptors