4.2 - Diffusion Flashcards
The process of simple diffusion The process of facilitated diffusion How different factors affect the rate of diffusion
What is diffusion?
Net movement of particles from high to low concentration
What is a concentration gradient?
Difference in concentration between two areas
What is equilibrium in diffusion?
Even distribution of particles
Is diffusion active or passive?
Passive
What are the two types of diffusion?
Simple and facilitated
What is simple diffusion?
Molecules diffusing directly across cell membranes
What type of molecules use simple diffusion?
Small and non-polar
What is facilitated diffusion?
Large or polar molecules crossing cell membranes
What are the two types of proteins involved in facilitated diffusion?
Carrier and channel proteins
Are carrier and channel proteins specific or non-specific?
Highly specific
What do carrier proteins transport?
Mainly large molecules
How do carrier proteins work?
Molecule attaches
What do channel proteins transport?
Mainly ions
How do channel proteins work?
Form pores in the cell membrane
What factors affect the rate of diffusion?
Temperature
How does temperature affect diffusion?
Higher temperature
How does concentration gradient affect diffusion?
Steeper gradient
How does membrane thickness affect diffusion?
Thinner membrane
How does surface area affect diffusion?
Larger surface area
How does the number of carrier/channel proteins affect diffusion?
More proteins
