Movement of Materials in and out of Cells Flashcards
What is Diffusion?
The net movement of particles from a region of high concentration to a region of low concentration down a concentration gradient
What is Osmosis?
The net movement of WATER from a dilute solution to a more concentration solution across the partially permeable cell membrane.
What is Active Transport?
It is the movement of substances against a concentration gradient, using energy from respiration.
What does Selectively Permeable mean?
A membrane that can control which chemicals can pass in and out
What factors increase/decrease the rate of movement?
Temperature - Rate is greater at higher temperatures. Higher temp provides particles with more kinetic energy
The Distance - Rate is decreased if the distance over which diffusion has to take place is greater
Surface Area to Volume Ratio - A larger surface area in proportion to the volume will increase the rate
Concentration Gradient - Diffusion happens more quickly when there is a steep concentration gradient (big difference in concentration between two areas)
IMPORTANT NOTE:
ACTIVE TRANSPORT REQUIRES ENERGY PROVIDED BY RESPIRATION
What is a partially permeable membrane?
A membrane that allows water and other small molecules to pass through, but not larger molecules such as starch.
