Diffusion Flashcards
Diffusion
The net movement of particles from an area of high concentration to an area of lower concentration.
In which state of substance does diffusion NOT happen?
Solids
Facilitated diffusion
The net movement of particles down a concentration gradient (i.e. from a region of high concentration to a region of lower concentration). Molecules diffuse through carrier proteins or channel proteins spanning across the membrane.
Aquaporins
Channel proteins that allow water to pass through the membrane.
What two proteins allow facilitated diffusion?
Carrier protein
Channel proteins
What would happen to the rate of diffusion if the concentration got steeper and the temperature rose?
The speed of diffusion would increase
The 5 Factors affecting diffusion:
- Temperature
- Thickness of membrane
- Number of channel proteins
- Membrane surface area
- Concentration gradient
What substances and diffuse across cell membranes?
Carbon dioxide
Oxygen
Urea
Does facilliated diffusion require (ATP) energy
No as it is a passive process
s the following statement true or false?
“Diffusion requires the input of energy.”
False because it is passive
During facillitated diffusion, the membrane protein changes shape to help transport the molecule across the bilayer.”
Which type of transport protein does this statement refer to?
Carrier protein
What would decrease the rate of simple diffusion?
Increasing the thickness of a membrane
Decreasing the surface area of the membrane
What is the name of the process that moves fatty acids across the plasma membrane?
Diffusion
Compare active transport and facilliated diffusion
- Active transport requires carrier proteins.
- Facilliated diffusion requires both channel proteins and carrier proteins
- Facilliated diffusion is a passive process.
- Active transport requires energy in the form of ATP
- Facilliated diffusion occurs down a concentration gradient.
- Active transport occur up against a concentration gradient
