1.6 Diffusion Flashcards
What is diffusion
Diffusion is the spreading out of particles of any substance in a solution or particles in a gas, resulting in a net movement of particles from an area of higher concentration to an area of lower concentration, down a concentration gradient
What factors affect diffusion
Difference in concentrations, temperature, and available surface area
How to work out net movement
nm = particles moving in - particles moving out
Describe the rate of diffusion
If there is a big difference in concentration (large concentration gradient) then diffusion will take place quickly
What do cells need
oxygen - respiration
minerals - bones/healthy organs
glucose- respiration
amino acids - making proteins
Explain why diffusion takes place faster when there is an increase in temperature
Heating makes particles move more quickly speeding up diffusion as particles collide more often and harder and spread out faster
What is a concentration gradient?
The difference between two areas of concentration. Diffusion occurs down a concentration gradient
What do cells need taken away
carbon dioxide
Where does oxygen go in diffusion
oxygen -> lungs -> red blood cells -> cells
where does glucose go in diffusion
glucose -> small intestines -> blood -> cells
where does amino acids go in diffusion
amino acid -> small intestine -> blood -> cells
where does minerals go in diffusion
minerals -> small intestine -> blood -> cells
where does carbon dioxide go in diffusion
carbon dioxide -> lungs -> blood -> cells
Explain why do many cells have folded membranes along at least one surface
Folded membranes provide increased surface area. The greater the surface area, the more diffusion of dissolved substances can take place across it
Does diffusion require energy
No, it is a passive process
Give examples of diffusion
oxygen moves from a high concentration in the lungs to a low concentration in the blood.
Why does diffusion take place?
Because of the random movement of particles
Describe the process of diffusion of digested food products from the gut to the bloodstream
Digested food molecules move from gut (high concentration) into the bloodstream (low concentration) down a concentration gradient.
Large surface area of small intestine lining increases rate of diffusion. Rich blood supply maintains concentration gradient.
Describe the process of diffusion when carbon dioxide moves from the blood to the lungs
Carbon dioxide moves from blood (high concentration) into air in the alveoli of the lungs (low concentration) down a concentration gradient.
Large surface area of alveoli increases rate of diffusion. Rich blood supply maintains concentration gradient.
Describe the process of diffusion when digested food products move from your gut to your bloodstream
Digested food molecules move from gut (high concentration) into bloodstream (low concentration) down a concentration gradient.
Large surface area of small intestine lining increases rate of diffusion.
Rich blood supply maintains concentration gradient.
Describe the process of diffusion occurring when male moths track down a mate up to 3 miles away due to the special chemicals produced by the female
Chemicals produced by female moth spread out into air around her down concentration gradient.
Chemicals more concentrated close to female moth (high concentration) than further away (low concentration). Male moth flies up concentration gradient, following chemical to reach
female moth.
