UNIT ONE; Cell Biology Flashcards
What does Specialised cells do?
This means they have a special shape or structure that allows them to carry out a specific function.
What does selectively permeable mean?
Only small particles can pass through easily.
What cell structure is Selectively permeable?
The cell membrane
How can large particles pass through the cell membrane?
Using channels made of protein.
How is the cell membrane made up.
Proteins (big circular) and the phospholipid bilayer (inbetween the proteins)
What is Diffusion?
Diffusion is the movement of molecules from an area of high concentration to an area of low concentration
Across a selectively permeable membrane.
Diffusion is Passive, what does this mean
No energy is required
What is osmosis?
The movement of water across a selectively permeable membrane from an area of high concentration of water molecules
to an area of low concentration of water molecules
What happens to a plant cell if water moves into it via osmosis?
It becomes turgid
What has happened to a cell in order for it to become in a turgid shape
Water has moved in via osmosis and due to the plant cell wall the water is held in. The cell begins to swell and pushes against the cell wall.
What happens to a plant cell if a lot of water leaves the cell via osmosis?
It will become Plasmolysed.
What has happened to a cell for it to be in a plasmolysed state
A lot of water has left the cell via osmosis and the cytoplasm will start to peel away from the cell wall and the plant will begin to wilt and die.
What happens when animal cells are placed in pure water?
Animal cells don’t have a cell wall so they will burst if water moves in
What happens when animal cells are placed in a salt solution?
If water moves out there is no cell wall to keep its original state so the cells will shrink and shrivel.
What is active transport?
Active transport is the movement of molecules from a low to a high concentration.
eg, against a concentration gradient.
