Flashcards in [2] class3 Zaidi-transport Thru Membranes Deck (77)
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1
Interactions involved in lipid bilayer:
Electrostatic and non covalent
2
These are frequently glycosylated on the extracellular side of the lipid bilayer
Membrane lipids and proteins
3
Integral membranes
All the way transmembrane through lipid bilayer
4
Plasma membrane is semi
Semi-permeable
5
________facilitate movement of specific molecules across the Plasma membrane
Membrane transport proteins
6
Several hydrophobic residues for one protein the enters and leaves PM several times:
polytopic
7
Most transport proteins are:
Polytopic transmembrane integral membrane proteins
8
What is advantage to polytopic membrane proteins?
Allows more diversity in binding and conformational changes
9
What is permeable to PM??
Lipophilic molecules via diffusion - steroid hormones
10
What is impermeable to the PM?
Hydrophilic/ polar substances
11
How can polar/hydrophilic molecules pass through PM?
Needs a specific transport mechanism
12
What is used for specific transport of molecules across PM?
Membrane proteins
13
Polytopic, transmembrane, integral membrane proteins can:
Have multiple transport domains and can shape the cell to allow more substances to pass
14
What determines the ionic composition of the cell?
The activity and protein levels of specific transporters
15
What governs the biochemical/metabolic characteristics of a cell?
Expression of specific transporters
16
One way of regulating metabolism
Alteration in expression levels of transporters
17
Ion gradient are they static?
No dynamic, but they could be thought of static in regard to they are quickly reestablished [in the way they're maintained]
18
Ion gradient allows for:
Membrane potential for AP
19
Brains uses _____ of energy
20%
20
Molecules move down a [ ] gradient by using energy stored in the gradient: Ex:
Passive transport ; ion channels
21
Molecules move against a gradient by using biochemical energy stored in ATP: EX:
Active transport; pumps/ ATPases
22
Energy independent movement of molecules down a gradient:
Passive transport
23
2 types of passive transport :
Simple diffusion
And
Facilitated diffusion
24
Molecules that are small, nonpolar, and uncharged move freely across PM unaided
Simple diffusion
25
Molecules that're large and charged unable to cross the PM w/o assistance of channel or transporter
Facilitated diffusion
26
____________ of molecules is asso. W. free energy
Unequal distribution
27
What is used to set up an ion gradient across a semi-permeable membrane?
Energy
28
Ion gradients are generated by:
Membrane transporters [energy transducers]
29
Membrane transporters use energy from and store it as free energy of the gradient
ATP
30
