KA1.2 - Transport Across Cell Membranes Flashcards
The cell membrane consists of … and …
Proteins and phospholipids.
A phospholipid and protein look like?
The phospholipid has a circular head with two legs:
O=
A protein looks like a circular blob:
O
How are passive and active transport different?
Passive transport does not need energy and movement is from a High concentration to Low concentration. Active transport needs energy and goes from a Low to a High.
What is the definition of diffusion?
is the movement of molecules from an area of high concentration to an area of low concentration down a concentration gradient.
What is the definition of osmosis?
where water molecules move from a high water concentration to a low water concentration down a concentration gradient through a selectively permeable membrane.
What are the two differences between diffusion and osmosis?
Osmosis needs a selectively permeable membrane and is the movement of only water.
The two examples of passive transport are … and …
Osmosis … diffusion.
Neither osmosis or diffusion require energy as they move from a High concentration to a Low concentration.
An animal cell will … if placed in a higher water concentration than inside the cell
Burst.
There is a concentration gradient moving into the cell from High concentration outside to Low concentration inside
What happens to an animal cell if it is placed into a solution with a lower water concentration that inside the cell?
Shrink.
There is a Low concentration outside the cell and High inside, so the water leaves the cell.
A plant cell will become … if placed in a higher water concentration than inside the cell.
Turgid.
The water moves into the cell.
What does plasmolysed mean?
It is a plant cell that has had the water leave it, as there was a high concentration inside the cell and low outside.
A … cell experiences turgid and plasmolysed states due to water moving in and out of the cell.
Plant cell.
…. transport requires energy to move molecules against the concentration gradient from an area of … concentration to an area of high concentration.
Active … low
Active transport requires energy to move molecules against the concentration gradient from an area of low concentration to an area of high concentration.
In the cell membrane, membrane …. are required for active transport
Membrane proteins.
Are proteins found in the cell membrane that act as buses to move molecules from one side of the cell membrane to the other, against the concentration gradient.
