Diffusion, osmosis and active transport Flashcards
(15 cards)
What is diffusion?
Diffusion is the net movement of a substance from an area of high concentration to an an area of low concentration, across a partially permeable membrane.
Does diffusion require energy and what type of process is this called?
Diffusion does not require energy and therefor is a passive process.
Does diffusion require energy and what type of process is this called?
Diffusion does not require energy and therefore is a passive process.
What 4 factors affect diffusion?
Temperature, surface area, concentration gradient and diffusion distance.
How does temperature affect diffusion?
As temperature increases the rate of diffusion also increases. Molecules gain more kinetic energy and move around faster. As a result more of the molecules move down the concentration gradient in a give time.
How does surface area affect diffusion?
The larger the surface area, the faster the rate of diffusion. In our bodies structures such as the alveoli in the lungs and villi in the small intestine help increase the diffusion of oxygen and digested food respectively.
How does surface area affect diffusion?
The larger the surface area, the faster the rate of diffusion. In our bodies structures such as the alveoli in the lungs and villi in the small intestine help increase the diffusion of oxygen and digested food respectively.
How does concentration gradient affect diffusion?
The steeper the concentration gradient the faster diffusion will take place. The bigger the difference in the concentration of the substance across the partially permeable membrane the quicker diffusion will take place.
How dies diffusion distance affect diffusion?
The shorter the diffusion difference, the faster the rate of diffusion will be. Many diffusion surfaces in our body are relatively thin in order to allow diffusion to take place as efficiently as possible.
What is osmosis?
Osmosis is the movement of a substance from an area of high water potential (no/little solute) to an area of low water potential (more solute) across a partially permeable membrane.
What is the effect of osmosis on an animal cell?
Animal cells do not have a cell wall, this means if osmosis takes place they will swell and expand, this is known as lysis. When an animal cell loses water it causes it to shrivel, this is also known as crenation.
What is effect of osmosis on a plant cell?
Plant cells have a cell wall and therefore swell to become turgid. When a plant cell loses water, the cell membrane pulls away from the cell wall and it is then considered plasmolysed.
What is active transport?
Active transport is the movement of a su
What is active transport?
Active transport is the movement of a substance from a an area of low concentration to an area of high concentration across a partially permeable membrane. It requires energy to take place.
Does active transport require energy to take place?
Active transport does require energy to take place.
