13 Osmosis+ Diffusion Flashcards
Selectively permeable membranes allow…
some substances to pass through easily, but other substances cant pass through easily
Diffusion is
•The movement of molecules from HIGH -> LOW concentration
•Passive(needs no energy)
Osmosis is
•The movement of WATER from a high water concentration to a low water concentration
•Passive
What happens to animal cells in a solution that is the same concentration as their cytoplasm?
Stay the same size
What happens to animal cells in a solution that is less concentrated than their cytoplasm
Gain water
May swell and burst
What happens to animal cells in a solution that is more concentrated than their cytoplasm
Lose water
Shrivel
Die
Amoeba is
a single-celled organism that lives in freshwater pools and ponds
Freshwater is less concentrated than the cell contents of amoeba so it needs to control osmosis or it will swell and burst
This is called the osmoregulation system
How does amoeba survive in a less concentrated environment (freshwater)
It survives because of its osmoregulation system which consists of a contractile vacuole which eliminates/expels water
What happens to plant cells in a solution that is less concentrated than their cytoplasm
Gain water
Become turgid and strong
What happens to plant cells in a solution that is more concentrated than their cytoplasm
Lose water
become weak
What can be used as food preservation techniques?
High salt concentration
High sugar concentration
Eg of food preserved in High Sugar Concentration
Jam
Marmalade
Eg of food preserved in High Salt Concentration
Fish(Anchovies)
Meat(Bacon)
How does osmosis work in food preparation
It dehydrates micro-organisms and prevents them from growing and kills them.
osmosis practical keywords
Visking tubing
Sucrose solution
Mass and turgidity
