H⁺-ATPases of plasma membrane and tonoplast are

Correct option is A

✅ (a) different
· Plasma membrane H⁺-ATPases are P-type ATPases.
· Tonoplast (vacuolar membrane) H⁺-ATPases are V-type ATPases.
· Both pump protons (H⁺) but differ in structure, energy utilization, and function.
· P-type uses ATP hydrolysis directly; V-type creates proton gradients for secondary active transport.
❌ (b) not known
· The types and mechanisms of H⁺-ATPases in both membranes are well-studied and established.
· Hence, incorrect.
❌ (c) same
· They are structurally and functionally different types of ATPases (P-type vs V-type).
· Incorrect to consider them the same.
❌ (d) None of the above
· Incorrect as (a) correctly explains their relationship.