3.2.3.2 - Simple and Facilitated Diffusion Flashcards
What is simple diffusion?
Simple diffusion is the passive net movement of molecules from an area of high concentration to an area of low concentration until evenly distributed.
Simple diffusion is an example of…………
passive transport
What is passive transport?
The energy comes from the natural and inbuilt motion of particles than external sources like ATP.
What kind of particles simply diffuses?
Small non-polar molecules e.g. oxygen, carbon dioxide, lipid-based hormones (steroids).
How do the particles diffuse across?
The particles diffuse across cell membranes down a concentration gradient.
Are there any proteins involved in simple diffusion?
no
What is Facilitated diffusion?
Facilitated diffusion is the passive net movement of large molecules or ions from an area of high concentration to an area of low concentration via transport proteins until evenly distributed.
Facilitated diffusion is an example of…………
passive transport - no ATP involved
What kind of particles diffuses by facilitated diffusion?
Large and polar molecules or ions e.g. glucose, Na+, K+.
How does facilitated diffusion differ from simple diffusion?
FD occurs at specific points on the plasma membrane where there are special protein molecules.
What are the two types of proteins involved?
Channel Proteins
Carrier Proteins
