Chapter 10

Question 1

Transport proteins are important for transmembrane movement of these ions and metabolites.

Answer 1

Na+, K+, Ca2+, and Cl- ; amino acids, sugars, nucleotides and water

Question 2

Diffusion of a Substance

Answer 2

A (out) A(in)

Question 3

If [A]out is greater than [A]in, delta (GA) will be ______. The net flow will be ________.

Answer 3

negative ; inward (spontaneous)

Question 4

If [A]in is greater than [A]out, delta (GA) will be _______. The net flow will be ________.

Answer 4

positive ; outside

Question 5

_____ differences change as ions (charged) go through the membrane.

Answer 5

Chemical potential

Question 6

1 V =

Answer 6

J/c

Question 7

If a reaction has a positive delta G (+), it needs to __________.

Answer 7

be coupled with a reaction to make it (-)

Question 8

Simple Diffusion

Answer 8

Small molecules just pass right pass through the membrane

Question 9

Passive Mediated Transport

Answer 9

Spontaneously flow from high to low concentration (no energy needed.

Question 10

Active Mediated Transport

Answer 10

Endergonic reaction ; flow from low to high concentration. Requires energy. It has to be coupled to an exergonic process.

Question 11

Carrier Ionophore process

Answer 11

1) comes to one side of the membrane
2) grabs ion
3) Goes through the other side of the membrane
4) Releases it
5) Repeats

Question 12

Valinomycin

Answer 12

A type of ionophore.

• Rolls up around K+ ions and methyl groups are on the outside
• Makes it an octahedral complex
• Becomes hydrophobic

Question 13

K+ channel

Answer 13

• Na+ ions can’t go through K+ channel
• The channel is super selective
• K+ has water molecules around it
• There is a selectivity filter.
• Complex scaffolding of water molecules
• As it goes through the filter, K+ replaces water for oxygens on proteins

Question 14

Why can’t Na+ go through the K+ channel?

Answer 14

It is not geometrically optimized to go through the channel. Too much energy would be needed.

Question 15

Substances too large or too polar are carried across the membrane through

Answer 15

• Carriers
• Permeases
• Channels
• Transporters

Question 16

Ionophores

Answer 16

Organic molecules (usually of bacterial origin) that increase the permeability of membranes to ions.

Question 17

Uniport

Answer 17

Translocation system where one molecule is moving at a time

Question 18

Symport

Answer 18

Translocation system where 2 different molecules are being transported at the same time as long as the channel is optimized for each molecule type.

Question 19

Antiport

Answer 19

Simultaneously transports two different molecules in opposite directions

Question 20

Aquaporin

Answer 20

• There are two asparagine residues inside the aquaporin channel. Apsaragine has a positive and negative end.
• Water is attracted into the aqua by the porin’s negative ends of the asparagines.

Question 21

Glucose Transport

Answer 21

1) Glucose molecule binds to the protein
2) The protein (specific to glucose) folds up around it
3) Goes through the membrane and releases the glucose (dissociates glucose)
4) System resets

Question 22

Na+-K+ ATPase is a type of ___________.

Answer 22

Active Transport, requires energy to push ions out of the gradient.

Question 23

Which is energy dependent?

Answer 23

Active Transport

Question 24

Which is energy independent?

Answer 24

Facilitated Transport, Simple Diffusion

Question 25

Which needs some kind of carrier protein(s)?

Answer 25

Facilitated Diffusion, Active Transport

Question 26

Which doesn’t need some kind of carrier protein?

Answer 26

Simple Diffusion

Question 27

Which can be saturated by substrate?

Answer 27

Facilitated Diffusion, Active Transport

Question 28

Which can establish a concentration gradient?

Answer 28

Facilitative Diffusion, Active Transport