transport across the cell membrane Flashcards
what does the cell membrane consist of?
Phospholipids and proteins and is selectively permeable.
what is passive transport?
passive transport occurs down a concentration gradient and doesn’t require energy.
what are two examples of passive transport?
Osmosis and Diffusion.
what is diffusion?
diffusion is the movement of molecules down a concentration gradient from high to low.
what are some substances that occurs in diffusion?
Oxygen , carbon dioxide and glucose
what is the function of osmosis?
Osmosis is the movement of water molecules from a higher water concentration to a lower water concentration through a selectively permeable membrane.
what happens to a animal cell placed in pure water?
it bursts.
what happens to an animal cell placed in a salty/sugary solution?
it shrinks.
what happens to a plant cell when placed in pure water?
becomes turgid.
what happens to plant cells when placed in salty or sugary solutions?
becomes plasmolysed.
what is active transport?
active transport is the movement of molecules against the concentration gradient and requires energy.
what’s a difference between passive and active transport?
active transport requires energy whereas passive does not.
