Diffusion and Osmosis Flashcards
Adaptions of plants?
- large surface area
- thin so carbon dioxide does not have to travel far
What is diffusion?
spreading of particles from an area of high concentration to an area of low concentration down a concentration gradient
Adaptions of the villi?
- large surface area
- thin walls
- good blood supply
What factor affect the rate of diffusion?
surface area
temperature
concentration gradient
What is required of a good gas exchange?
- large surface area
- short diffusion pathway
- good blood supply
What is osmosis?
diffusion of water from a dilute solution to a concentrated solution through a partially permeable membrane
What is active transport?
movement of substances down a concentration gradient
What process requires energy from respiration?
active transport
Percentage change in mass
change in mass / initial mass x 100
Why do you need to cut the potatoes in even sizes?
same surface area
Why is it important to dry the potatoes chips before recording their masses?
to make sure only the mass of the potato is being recorded to make the investigation accurate
How does temperature affect the rate of diffusion?
higher the temperature, the faster the rate of diffusion
particle gain kinetic energy and diffuse in and out of cells more quickly
How does surface area affect the rate of diffusion?
the larger the surface area, the faster the rate diffusion
more particles can diffuse in and out of the cell
How does the concentration gradient affect the rate of diffusion?
the more steeper the concentration gradient, the faster the rate of diffusion
Explain the adaptions of the alveoli?
large surface area for gas exchange
sone cell thick create a short diffusion path so carbon dioxide does not have to diffuse far into the leaf
good blood supply to maintain a concentration gradient
Explain the adaptions of plants?
large surface area to maximise absorption of carbon dioxide
thin so carbon dioxide does not have to diffuse far into the leaf
How do calculate total surface area?
area of each face x the number of faces
control variables on the osmosis practical:
mass of potato chips
Independent variables in the osmosis practical:
concentrations of sugar solution
If the potato chip has decreased in mass…
it has lost water through osmosis
If the potato chip has increased in mass…
it has gained water through osmosis
If there is no change in mass..
the concentrations of solutions and the potato sap are equal
Why cannot multi-cellular organisms only rely on diffusion?
surface area to volume ratio is too small
Give examples of diffusion in plants?
carbon dioxide diffuses in plants
oxygen diffuses out of plants
water absorption from the roots
water lost from transpiration
Why is diffusion important?
take in products for use in cells
remove waste products
Why do plant cells not burst?
they have a cell wall which stops the cell from bursting
Why do red blood cell burst?
do not have a cell wall
What is a partially permeable membrane?
allows certain substances
