Active Transport And Osmosis Flashcards
Osmosis
Movement of water from an area of high water potential to an area of low water potential through a semi permeable membrane
Hypotonic
A substance that has a low solute concentration and a high water potential
Isotonic
A solution that has the same solute content as water potential
Hypertonic
Substance has a high solute concentration and a low water potential
Concentration gradient
The difference between the number of particles in a high concentration area and a concentration area
Haemolysis/lysed
When the red blood cell gained so much water due to osmosis that they burst this is because they don’t have a cell wall
Lysis
The breakdown of a cell caused by damage to its outer membrane
Plasmolysed
When a plant cell loses so much water due to osmosis that the cell membrane moves and shrinks away from the cell wall
Flaccid
When the cell has lost so much water, that the cytoplasm shrinks away from the cell wall
Turgid
That has gained so much water, due to osmosis, that is unable to hold anymore water and becomes swollen, stretching the cell wall to the point of bursting
In osmosis water will
Move from an area of HIGH concentration to low concentration
Net movement of water (in osmosis
Overall movement of water from a dilute solution to a concentrated solution
Partially permeable membrane (in osmosis)
Will allow only water to pass through, and won’t let larger dissolved molecules pass through
What is diffusion
Diffusion is the net movement of particles from an area of high concentration to an area of lower concentration
What is active transport
- Active transport is the net movement of particles against a
concentration gradient.
• Energy is therefore required.
Examples of active transport in humans and plants
Mineral absorption in plants - mineral ions are nessacary for growth
Sugar absorption in the human gut - sugar molecules are needed for cell respiration
Factors that will increase the concentration gradient in gas exchange
- more ventilation
- big concentration difference
Examples of exchange surfaces
Roots - taking up north water and minerals from the soil around them
Lungs - • The lungs are adapted for exchanging carbon dioxide and oxygen
between the blood and air.
Small intestine - The small intestine is adapted for exchanging nutrients between digested food in the small intestine and the blood.
Gills - The gills are adapted for exchanging oxygen that is dissolved in water, with the carbon dioxide in a fish’s bloodstream.
Why is it bad if the alveoli in your lungs break down
The alveoli help increase the SA:V ratio of the lungs
If sacks are broken the SA:V ratio will decrease meaning diffusion will occur slower
The cube wi5h the largest SA:V ratio changed colour the fastest.
Use this to explain why most large multicellular organisms need transport system, such as the circulatory system, but most single celled organisms do not
-> cube with largest SA:V ratio changed colour quickest
-> single celled organisms have a high SA:V ratio meaning diffusion takes places quick,er and more efficiently than in multi celled systems
