Answer – Active transport requires energy to move molecules against their concentration gradient, whereas passive transport involves the movement of molecules along their concentration gradient without any energy input.
Explanation:
In active transport, a cell’s molecules or ions move from an area of lower concentration to an area of higher concentration. The energy is often provided by adenosine triphosphate (ATP). The sodium-potassium pump in nerve cells is a great example of active transport. This pump actively transports sodium ions out of the cell and potassium ions into the cell, against their respective concentration gradients.
In passive transport, molecules or ions in a cell flow from an area of higher concentration to an area of lower concentration. Hence, there’s no energy required. Adding sugar to a glass of water is an example of passive transport. The sugar crystals move from an area of higher concentration (undissolved sugar) to an area of lower concentration (water) until equilibrium is reached. Diffusion and osmosis are also types of passive transport.
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