Membrane Transport Flashcards

1
Q

Passive processes of transport

A

osmosis, facilitated diffusion, diffusion, bulk filtration

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2
Q

Functions of the Plasma Membrane

A

Physical Barrier, Gateway for exchange, Communication, Site of Attachment

other cells, extracellular and intracellular proteins

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3
Q

What part of the plasma membrane aids in communication?

A

receptors

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4
Q

Simple Diffusion

A

the random motion of molecules in solution (results in the spread of molecules from areas if high concentration to areas of low concentration

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5
Q

What does Jnet mean in Fick’s Law of Diffusion

A

Net Flux

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6
Q

What does the Fick’s Law of Diffusion mean in words

A

Flux equals the negative of the product of solute diffusion coefficient (Ds) and solute concentration gradient (dCs/dx)

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7
Q

What factors increase the rate of diffusion?

A

temp, area, membrane permeability, and lipid solubility

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8
Q

What decreases the rate of diffusion?

A

membrane thickness and molecular size

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9
Q

Why is the equation for Fick’s Law of Diffusion negative?

A

up= outside the cell
down= inside the cell
negative from going up to down
fluxing in

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10
Q

A decrease in the concentration gradient will.. increase or decrease flux?

A

decrease

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11
Q

What are the major things that are going to affect the rate of diffusion?

A

membrane permeability and concentration gradient

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12
Q

In Einstein’s Solution of Fick’s eq, what is D

A

diffusional coefficient

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13
Q

In Einstein’s Solution of Fick’s eq, what is d

A

distance

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14
Q

Osmosis in respect to solutes

A

low solute concentration to high solute concentration

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15
Q

bulk filtration

A

the concentrated movement of large groups of molecules, often including water (often in response to pressure)

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16
Q

What are the active processes of transport?

A

protein-based transporters and pumps

17
Q

Channels

A

usually for ions; passive, classical “facilitated diffusion”

18
Q

Carriers

A

Doorman mechanism; uniport, symport, antiport; may be active or passive

19
Q

Pumps

A

typically for ions; active: require direct energy usage (ATP)

20
Q

Ion Channels

A

membrane proteins that act as a passive conduit for ions through the membrane

21
Q

When open ion channels permit __________ ________ of ions

A

passive diffusion

22
Q

Channelopathies

A

Diseases or disorders associated with ion channel dysfunction

23
Q

Are channels or transporter faster?

A

channels (transporters are not designed for speed) (just like ur mom)

24
Q

Alternating access model

A

carrier proteins cycle between multiple conformations in which a solute binding site is accessible on one side of the membrane or the other

25
Q

With carrier proteins, is there ever a open channel all the way through the membrane?

A

no.

26
Q

What is secondary active transport?

A

utilizes energy stored in a pre-existing concentration gradient

27
Q

What happens in the Na/K pump

A

3 Na out, 2 K in