1.2 transport across the cell membrane

What is the cell membrane?

Selectively permeable (only certain molecules are able to pass through)

What do the proteins look like in a cell membrane?

Large blob like structures (circles)

What do phospholipids look like in a cell membrane?

The smaller tadpole like structures (rectangle)

What can move into the cell through the membrane?

Glucose, oxygen and amino acids

What can move out of the cell through the membrane?

Carbon dioxide (and urea)

What can glucose move through a membrane but starch cannot?

This is because starch molecules are too big to move through the membrane.

What way can you move (without using energy) on the concentration gradient?

From a high concentration to a low concentration

What is diffusion?

The movement of molecules from an area of high concentration to an area of low concentration.

What does passive mean?

Does not require energy

What is osmosis?

Movement of water molecules from an area of high water concentration to an area of low water concentration

What is active transport?

\
The movement of molecules or ions against the concentration gradient.

What does active transport need to help it work?

Membrane proteins along with energy

What would happen if you put an animal cell into an area of high water concentration?

The cell would swell up and burst. (this is because there is no support from a cell wall) Water enters the cell.

What would happen if you put an animal cell into an area of low water concentration?

The cell would shrink. Water exits the cell.

What would happen if you put a plant cell into an area of high water concentration?

The cell would become turgid. Water would move into the cell, the vacuole would swell and press up against the cell wall.

What would happen if you put a plant cell into an area of low water concentration?

The cell would become plasmolysed. Water exits the cell, the vacuole empties and the cell membrane moves away from the cell wall.

Anthocyanin is held in the vacuole by the vacuole membrane.

What is in a beetroot that colours it and where is that held in the cell?

What way can you move (using energy) on the concentration gradient?

From a low concentration to a high concentration, this is called active transport.