Deck 11: Active Transport: Pumps and Exchangers

Question 1

An ex am ple of a prim ar y ac tive tra ns po rt m ec ha nis m is

A) SGLT-1
B) NHE
C) NCX
D) SERCA
E) NIS

Answer 1

D

Question 2

Secondary active transport mechanisms

A) Hydrolyze ATP
B) Co up le m ov em en t of o ne m ater ial dow n its electrochemical gradient with another solute moving up its electrochemical gradient
C) Cannot concentrate solutes
D) Are facilitated diffusion mechanisms
E) Ar e n ot s atu ra ble

Answer 2

B

Question 3

The sto ich iom etr y of t he Na ,K- AT Pa se is

A) 3 Na+ ions are pumped into the cell with 2 K+ ions being pumped out
B) 3 Na+ ions move in and 1 Ca₂+ ion moves out
C) 1 Na+ ion m ov es ou t with ev er y K+ ion tha t m ov es in
D) 3 Na+ ions are pum ped out of the cell with 2 K+ ion s be ing pu m pe d in
E) 3 Na+ ions are pumped out of the cell with each K+ ion be ing pu m pe d in

Answer 3

D

Question 4

For most cells in the body, the intracellular free [Ca₂+] is about

A) 12 mM
B) 1.2 mM
C) 0.12 mM
D) 10.2 µM
E) Less than 1µ M

Question 5

A symport is a transport mechanism that

A) T ra ns po rts ion s a cr os s th e s ym ph ysis
B) Transports two solutes in the same direction
C) Transports one solute down its electrochemical gradient
D) Transports two solutes in opposite directions
E) Transports one solute up its electrochemical gradient

Question 6

The electrochemical potential for an ion in solution is given as

A) µ = RT ln C + z ; ¡
B) µ = µ0 + RT C + z ; ¡ 6 C + z ; 6¡
D) µ = µ 0 + RT ln C + z ; ¡
E) µ = -RT ln K eq

Question 7

Which of the following is a secondary active transport mechanism?

A) Na,K-ATPase
B) PMCA
C) NCX
D) SPCA
E) SERCA

Question 8

Which of the following does NOT work through a primary active transport mechanism?

A) SERCA
B) Na,K-ATPase
C) PMCA
D) SG LT -1
E) H-K-ATPase

Question 9

The sto ich iom etr y of t he NC X is

A) 3 Na+ ions for every Ca₂+ ion
B) 2 Na+ ions for every Ca₂+ ion
C) 1 Na+ ion for every Ca₂+ ion
D) 3 Na+ ions for every 2 Ca₂+ ions
E) 2 Na+ ions for every 2 Ca₂+ ions

Question 10

Primary active transport mechanisms

A) Use the energy of the Na+ grad ient to p owe r "up hill" trans port o f ano ther s olute
B) Hydrolyze ATP
C) Are facilitated diffusion mechanisms
D) Cannot concentrate solutes
E) Transport only ions

Question 11

Which of the following is NOT a secondary active transport mechanism?

A) H,K-ATPase
B) SG LT-1
C) NCX
D) NIS
E) NHE

Question 12

For most cells in the body, the extracellular [Na+] is abo ut

A) 290 mM
B) 145 mM
C) 60 mM
D) 12 mM
E) 4 mM

Question 13

An ex am ple of a sym po rt is

A) SGLT1
B) NCX
C) NHE
D) AE
E) Na,K-ATPase

Question 14

Active Transport mechanisms

A) Equilibrate the concentration of a solute across a mem brane
B) Move at least one substrate from a region of lower electrochemical potential to a region of higher electrochemical potential
C) Do not respond to differences in potential across a mem brane
D) Move only ions
E) Do not require metabolic energy

Question 15

For most cells in the body, the intracellular [Na+] is about

A) 290 mM
B) 145 mM
C) 60 mM
D) 12 mM
E) 4 mM

Question 16

Active transport differs from passive transport in that

A) Ac tive tra ns po rt is sa tur ab le w he re as pa ss ive tra ns po rt is no t sa tur ab le
B) Active transport requires metabolic energy whereas passive transport does not
C) Active transport displays competition whereas passive transport does not
D) Active transport moves things from high to low electrochemical potential whereas passive transport moves them the other way
E) Active transport involves proteins, whereas passive transport does not