Pumps - P-type ATPases

Question 1

P-type ATPases

Answer 1

~ large alpha catalytic subunit
~ some have beta subunits
~ pump cations (+ve)

Question 2

The Na+/K+ ATPase in animal cells - LOCATION

Answer 2

PM of animal cells

Question 3

The Na+/K+ ATPase in animal cells - SUBSTRATE

Answer 3

3Na+:2K+ per ATP hydrolysed

Question 4

The Na+/K+ ATPase in animal cells - FUNCTION

Answer 4

a) maintains high K+ and low Na+ in the cytosol - important in action potential generation.
b) maintain Na+ electrochemical potential – Na+ coupled transport

Question 5

The Na+/K+ ATPase in animal cells - STRUCTURE

Answer 5

2 alpha and 2 beta subunits

Question 6

The Na+/K+ ATPase in animal cells - INHIBITOR

Answer 6

Ouabain

Question 7

Fungal and Plant H+ ATPase - LOCATION

Answer 7

all Pms of plants nd fungal cells

Question 8

Fungal and Plant H+ ATPase - SUBSTRATE

Answer 8

1H+ per ATP hydrolysed

Question 9

Fungal and Plant H+ ATPase- FUNCTION (5)

Answer 9

a) to expel excess H+ produced during metabolism
b) generate a H+ electrochemical gradient (drives H+-coupled transport)
c) maintain -ve transmembrane voltage (>-200 mV)
d) regulate cytosolic pH
e) acidification of extracellular medium (loosen cell walls)

Question 10

Fungal and Plant H+ ATPase - STRUCTURE

Answer 10

1 alpha subunit

Question 11

Sarcoplasmic endoreticulum Ca2+ ATPase (SERCA) - LOCATION

Answer 11

sarcoplasmic reticulum network of tubules in the muscle cell cytoplasm forming stores of Ca2+

Question 12

Sarcoplasmic endoreticulum Ca2+ ATPase (SERCA) - SUBSTRATE

Answer 12

2Ca2+ per ATP

Question 13

Sarcoplasmic endoreticulum Ca2+ ATPase (SERCA) - FUNCTION

Answer 13

restore low cytosolic Ca2+ after muscle contraction

Question 14

Sarcoplasmic endoreticulum Ca2+ ATPase (SERCA) - STRUCTURE

Answer 14

1 alpha subunit

Question 15

Sarcoplasmic endoreticulum Ca2+ ATPase (SERCA) - INHIBITOR

Answer 15

Thapsigargin

Question 16

Plasma membrane Ca2+ ATPase (PMCA ATPase) - LOCATION

Answer 16

Fungal, plant, animal PMs

Question 17

Plasma membrane Ca2+ ATPase (PMCA ATPase) - SUBSTRATE

Answer 17

1-2 Ca2+ per ATP

exchanged for a H+

Question 18

Plasma membrane Ca2+ ATPase (PMCA ATPase) - FUNCTION

Answer 18

Maintain low cytosolic Ca2+

high = toxic

Question 19

Plasma membrane Ca2+ ATPase (PMCA ATPase)

- STRUCTURE

Answer 19

1 alpha subunit

Question 20

Gastric muscosal H+/K+ ATPase - LOCATION

Answer 20

PM of gastric epithelium cells

Question 21

Gastric muscosal H+/K+ ATPase - SUBSTRATE

Answer 21

2K+:2H+ per ATP hydrolysed

~ electroneutral

Question 22

Gastric muscosal H+/K+ ATPase - FUNCTION

Answer 22

H+ secretion in to the lumen of the stomach – acidic stomach

Question 23

Gastric muscosal H+/K+ ATPase - STRUCTURE

Answer 23

2 alpha and 2 beta subunits