Unit 1.2: transport in cells Flashcards
Define diffusion
Massive movement of molecules from a higher concentration to a lower
Define concentration gradient
The difference in concentration of a substance between two areas such as the inside and outside of a cell
What are the two molecules that make up the cell membrane?
Phospholipids and proteins
Define osmosis
Movement of water from a higher water concentration to a lower water concentration
Define active transport
Movement of molecules and ions against a concentration gradient which requires energy
Define passive transport
Movement of molecules down a concentration gradient which does not require energy
What would happen if an animal cell was put in a solution with a high water concentration?
It would absorb the water then grow and burst
What would happen if an animal cell was placed in a solution with a low water concentration?
Water would diffuse out of the cell then it would shrink and shrivel up
What would happen if a plant cell was placed in a solution with a high water concentration?
It would absorb the water and then swell and become turgid
What would happen to a plant cell if it was placed in a solution with a low water concentration?
Water would diffuse out of the cell and then become plasmolysed
What’s the function of the cell membrane?
Controlling what goes in and out of the cell
What molecules make up the cell membrane?
Proteins and Phospholipids
Define selectively permeable membrane?
Only certain molecules can enter and leave the cell
What molecules can go through the cell membrane?
Water, Oxygen, carbon dioxide, glucose
What molecules cannot go through the cell membrane?
Starch, protein
