Key Area 2 Transport Across Cell Membranes Flashcards
What is a cell membrane
The structure that controls movement of molecules into and out of a cell
What is Phospholipids
Molecules that make up the cell membrane with proteins.
What is a selectively permeable
Allows some molecules through but not others.
What is passive transport
Movement of molecules that does not require energy.
What is a concentration gradient
When there is difference in concentration on each side of a cell membrane.
What is diffusion
The movement of molecules from higher concentration to lower concentration, down a concentration gradient.
What is osmosis
The movement of water from higher water concentration to a lower water concentration, through a selectively permeable membrane.
What is turgid
A plant cell that has filled up with water.
What is plasmolysed
A plant cell that has shrunk as water moved out of it.
What is active transport
The movement of molecules and ions against the concentration gradient that requires energy.
If an animal cell is placed in salty and sugary solution
The animal cell would shrink, water moves out of the cell by osmosis.
If an animal cell is placed in pure water
The animal cell, water moves into the cell by osmosis.
If a plant cell was placed in a salty or sugary solution
The plant cell would become plasmolysed, water moves out of the cell by osmosis.
If a plant cell was placed in pure water
The plant cell would become turgid, water moves into the cell by osmosis.
Passive transport summary
No energy required
Molecules move down the concentration gradient.
