Answer:
c. Active transport
Explanation:
The differences between the different type of a substance's movement through a membrane (phospholipid bilayer) are:
- Passive transport: is the movement of substances across the membrane without needing ATP energy. Encompass facilitated diffusion and osmosis.
Facilitated diffusion: requires a transmembrane protein but the substances move in favor of their concentration gradient (this process doesn't need ATP energy).
Osmosis: when the molecules are not polar they can diffuse through the membrane, as long as they move in favor of their concentration gradient. So this process doesn't need transport proteins neither ATP.
- Active transport: polar molecules or ions require both a transmembrane transport protein and ATP energy when they move from a region of lower concentration to a one higher concentration, meaning, against the concentration gradient.
