Question

question 15
2 pts
how is active transport different from passive transport?
active transport requires energy, while passive transport does not.
active transport moves substances down the concentration gradient, while passive transport moves them against it.
active transport uses protein channels, while passive transport does not.
active transport only moves water, while passive transport moves other molecules.

Explanation:

Active transport is a process that requires energy (usually in the form of ATP) to move substances against their concentration gradient. Passive transport, on the other hand, does not require energy and moves substances down their concentration gradient. Let's analyze each option:

• Option 1: Active transport requires energy (e.g., ATP hydrolysis), while passive transport (like simple diffusion, facilitated diffusion) does not. This is correct.
• Option 2: Active transport moves substances against the concentration gradient, and passive transport moves them down the concentration gradient. So this option has it reversed.
• Option 3: Both active transport (e.g., carrier - mediated active transport) and some forms of passive transport (facilitated diffusion) use protein channels or carriers.
• Option 4: Osmosis (a form of passive transport) moves water. Active transport moves various molecules (e.g., ions like \(Na^+\), \(K^+\) etc.) against their concentration gradient.

Answer:

active transport requires energy, while passive transport does not.