Question

definition the movement by energy of molecules across a cell membrane from low to high concentration choose an answer 1 osmosis 2 facilitated diffusion 3 passive transport 4 active transport

Explanation:

• Option 1: Osmosis is the movement of water across a semi - permeable membrane, usually from high to low water concentration (or low to high solute concentration), and it is a type of passive transport (no energy input for the water movement itself in the basic sense), so it does not match the description of moving from low to high concentration with energy input.
• Option 2: Facilitated diffusion is a type of passive transport where molecules move from high to low concentration with the help of transport proteins. It does not require energy and moves down the concentration gradient, so it is incorrect.
• Option 3: Passive transport is the movement of molecules from high to low concentration (down the concentration gradient) without the input of energy. So this is the opposite of what the definition is asking for.
• Option 4: Active transport is defined as the movement of molecules across a cell membrane from an area of low concentration to an area of high concentration (against the concentration gradient), and this process requires energy (usually in the form of ATP) to occur. This matches the given definition.

Answer:

1. active transport