[2] class3 Zaidi-transport Thru Membranes Flashcards Preview

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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

Energy is minimum when [ ] across a semi-permeable mebrane is:

Equal