Summary
Highlights
What is Diffusion?00:00:06
Diffusion is the spreading out of particles, resulting in a net movement from an area of higher concentration to an area of lower concentration. This process is how molecules enter and leave cells.
Molecules that Diffuse00:00:50
Key molecules that move in and out of cells by diffusion are oxygen, carbon dioxide, and urea. Oxygen diffuses into cells for respiration, carbon dioxide diffuses out as a waste product, and urea, another waste product, diffuses out into the bloodstream.
Factors Affecting Diffusion Rate: Concentration Gradient00:02:11
The first factor affecting the rate of diffusion is the difference in concentrations, known as the concentration gradient. A greater concentration gradient leads to faster diffusion.
Factors Affecting Diffusion Rate: Temperature00:02:57
The second factor is temperature. Higher temperatures increase the rate of diffusion because particles have more kinetic energy and move faster.
Factors Affecting Diffusion Rate: Surface Area00:03:10
The final factor is the surface area of the membrane. A larger surface area of the cell membrane allows for a greater rate of diffusion.