U1 Transport Across Cell Membranes Flashcards
What are the properties of cell membrane?
It is selectively permeable, it also contains phospholipids and proteins
What is passive transport?
The movement of molecules from an area of high concentration to low concentration
Examples of passive transport
Osmosis and diffusion
What is the definition of osmosis?
The movement of water molecules down a concentration gradient through a semi-permeable barrier
What is the definition of diffusion?
The movement of molecules down a concentration gradient
What is active transport?
The movement of molecules from an area of low concentration to an area of high concentration - it requires energy as proteins push the molecules.
What happens to an animal cell when placed in water?
The cell bursts
What happens to an animal cell when placed in a salt solution?
It shrinks
What happens to a plant cell when placed in water?
It becomes turgid
What happens to a plant cell when placed in a salt solution?
It becomes plasmolysed
