Question

Two types of transport of molecules across a cell membrane are:

Transport 1: Solute molecules move across the cell membrane along their concentration gradient; requires no energy expenditure.
Transport 2: Solute molecules move across the cell membrane against their concentration gradient; requires expenditure of energy.
Which statement is CORRECT?

Select one:
a. Transport 2 describes passive transport by the Na+/K+ pump.
b. Transport 2 describes passive transport by a carrier protein.
c. Transport 1 describes facilitated transport of substances through the membrane.
d. Transport 1 describes passive transport by diffusion.

Answer 1

d. Transport 1 describes passive transport by diffusion.