Q. In photoactive plants, during day time the following ionic flux of guard cell is directly involves the expenditure of energy.
A) Outward movement of malate
B) Inward movement of potassium ions
C) Outward movement of protons
D) Inward movement of chloride
Explanation
Ion movement into and out the guard cells during stomatal closure and opening depends on proton pumping of ATPase, which provides the proton gradients that are coupled to other secondary active transport mechanisms for $K^{+}and\ Cl^{-}.$ The outward movement of protons is directly involves in expenditure of energy.
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.