B1 Flashcards
Define Osmosis
a process by which molecules pass through a semipermeable membrane from a dilute solution into a concentrated one.
What happens when animals cells are placed in a dilute solution and what is the process called?
There is more water outside the cell so more water comes into the cell. This causes the cells to swell and eventually burst due to their being no cell wall. This is called lysis.
What happens when animal cells are placed in a more concentrated solution and what is the process called?
There is more water inside the cell which means that water will rush out of the cells to surroundings which are more concentrated. If the cell looses too much water it becomes shrivelled up. This is called Crenation.
What happens when a plant cell is placed in a dilute solution?
There is more water outside the cell. This meaning water will enter the cell through Osmosis. This means the cell will start to swell up and become turgid.
What happens when a plant cell is placed in a More concentrated
solution?
There is more water inside the cell, so the water will leave the cell. This causes the cell membrane to pull away from the cell wall. The cell will now become soft. This is now called a Plasmolysed cell.
What does the water molecules pass through when going in or out of the cell?
Partially permeable membrane.
Nucleus
Controls all movements in the cell.
Cytoplasm
Most chemical reactions for life take place here.
Cell membrane
Controls the passage of substances.
Mitochondria
Where respiration takes place.
Ribosomes
Where protein synthesis takes place.
What do Eukaryotic cells contain?
Cell membrane, cytoplasm and genetic material which is enclosed in a nucleus.
What does a prokaryotic cell contain?
A cytoplasm and a cell membrane surrounded by a cell wall.
Examples of specialised cells
Nerve cells, muscle cells and muscle cells.
Why are some plant cells specialised?
To carry out a specific function.
