Short Quiz on SODIUM-POTASSIUM PUMP
Instruction
2. There is 1 Mark for each correct Answer
Cells maintain a low intracellular Na+ concentration and a high intracellular K+ concentration by sodium-potassium pump which is an example of:
Some carriers transport substances against their electrical and chemical gradients. This form of transport requires energy and is called active transport. In animal cells, the energy is provided almost exclusively by the hydrolysis of ATP. One of these ATPases is sodium-potassium adenosine triphosphatase (Na, K ATPase), which is also known as the Na, K pump.
C i.e. 3 : 2
- Na+-K+ pump extrudes –
– 3 Na+ out from cell.
– Pumps 2 K+ into cell.
- Coupling ratio of Na+-K+pump – 3:2.
A i.e. Involves ATPase activity
True regarding Na+ – K+ pump
B i.e. Hetrodimer hetrogenous
Extracellular binding site on Na+ – K+ pump is
D i.e. Ouabain.
Structure:
- Na+-K+pump-Carrier protein – Heterodimer.
- Made of two separate globular proteins:
– Larger α-subunit –
- Molecular weight -100,000
– Smaller β-subunit –
- Molecular weight – About 55,000.
- Na+ & K+ transport occurs through α-subunits.
- Both α- & β- subunits span across the membrane with an intracellular & extracellular site.
- The intracellular site has,
– 3 Na2+binding/receptor sites for Na+.
– An ATP binding site.
– A phosphorylating site.
– ATPase activity.
- The extracellular site has,
– 2 K+ binding/receptor sites for K+.
– An Ouabain binding site.
- 3 extracellular glycosylation sites.
- All 3 attached carbohydrate residue.
Binding site present on β unit of Na+ – K+ pump is
D i.e. Glycosylation.
Structure:
- Na+-K+pump-Carrier protein – Heterodimer.
- Made of two separate globular proteins:
– Larger α-subunit –
- Molecular weight -100,000
– Smaller β-subunit –
- Molecular weight – About 55,000.
- Na+ & K+ transport occurs through α-subunits.
- Both α- & β- subunits span across the membrane with an intracellular & extracellular site.
- The intracellular site has,
– 3 Na2+binding/receptor sites for Na+.
– An ATP binding site.
– A phosphorylating site.
– ATP’ase activity.
- The extracellular site has,
– 2 K+ binding/receptor sites for K+.
– An Ouabain binding site.
- 3 extracellular glycosylation sites.
- All 3 attached carbohydrate residue.
A i.e. is K+ pumped against the gradient
The sodium- potassium pump is an example of:
A i.e. Active transport
Some carriers transport substances against their electrical and chemical gradients. This form of transport requires energy and is called active transport. In animal cells, the energy is provided almost exclusively by the hydrolysis of ATP. One of these ATPases is sodium-potassium adenosine triphosphatase (Na, K ATPase), which is also known as the Na, K pump.
Sodium-potassium pump is a type of ‑
Ans. is ‘b’ i.e., Primary active transport
