2. Movement Into And Out Of Cells Flashcards
Diffusion
The movement of particles from an area of high concentration to low concentration (down the concentration gradient) until equilibrium is reached
Does diffusion require energy
No
Diffusion is a what process?
Passive process
What can diffuse through cell membranes
Very small molecules- glucose, amino acids, water, oxygen
What can’t diffuse through cell membranes
Big molecules- starch and proteins
How does oxygen diffuse into a cell
The concentration of oxygen molecules is greater outside the cell than inside
Osmosis
The diffusion of water molecules from an area of high water potential (concentrated) to an area of low water potential (diluted) through a partially permeable membrane
Which way can water molecules pass through the membrane during osmosis
Both ways
4 factors that affect the rate of diffusion
- increasing surface area
- decreasing the diffusion pathway
- increasing the concentration gradient
- increasing temperature
How does water enter the roots of plants
By osmosis
Active transport
Movement of particles from an area of low to high concentration (up the gradient) - requires energy from respiration
Plants using active transport eg
Root hair cells actively transport mineral ions from the soil into the root
Animals using active transport eg
Sugars are actively transported out of your gut or kidney
