Question

the movement of substances from lower to higher concentration across a semipermeable membrane via a specific protein carrier and cell expenditure of energy is called ___.
a facilitated diffusion
b diffusion
c osmosis
d endocytosis
e active transport

Explanation:

• Facilitated diffusion (A) is the movement of substances from higher to lower concentration via protein carriers without energy expenditure.
• Diffusion (B) is the movement of substances from higher to lower concentration without protein carriers or energy.
• Osmosis (C) is the movement of water from lower to higher solute concentration across a semi - permeable membrane without energy (passive).
• Endocytosis (D) is a process where the cell membrane engulfs substances (not the described movement across the membrane via protein carrier).
• Active transport (E) is the movement of substances from lower to higher concentration across a semi - permeable membrane via a specific protein carrier and with cell expenditure of energy.

Answer:

E. active transport