Question

Other ions, Na⁺, K⁺, and Ca²⁺, move against the concentration gradient; this required energy input and is called ________________.

a) Osmosis
b) Facilitated diffusion
c) Active transport
d) Passive transport

Answer 1

The movement of ions such as Na+, K+, and Ca2+ against their concentration gradient is called active transport, requiring ATP energy.

Step-by-step explanation:

The process of moving ions such as Na+, K+, and Ca2+ against their concentration gradient is known as active transport. Unlike passive transport, which includes diffusion, osmosis, and facilitated diffusion, active transport requires energy input. This energy often comes from ATP (adenosine triphosphate), which the cell generates through cellular respiration. An excellent example of an active transport mechanism is the sodium-potassium pump, which moves sodium and potassium ions against their concentration gradients, thereby maintaining essential concentrations of these ions within the cell's fluid compartments.