Diffusion Flashcards
Cell Biology (13 cards)
What is diffusion?
The gradual movement of particles from places where there are lots of them to places where there are fewer of them.
Diffusion is the natural tendency for stuff to spread out.
Define diffusion in a more formal way.
DIFFUSION is the SPREADING OUT of particles from an area of HIGHER CONCENTRATION to an area of LOWER CONCENTRATION.
In what states of matter does diffusion occur?
Diffusion occurs in both solutions and gases.
What is the simplest type of diffusion?
The simplest type is when different gases diffuse through each other.
What does the diffusion of perfume in a room illustrate?
It illustrates how perfume particles diffuse through the air.
How does concentration gradient affect diffusion rate?
The bigger the concentration gradient, the faster the diffusion rate.
What effect does temperature have on diffusion rate?
A higher temperature increases the diffusion rate because particles have more energy and move around faster.
What is the function of cell membranes in relation to diffusion?
Cell membranes hold the cell together and allow substances to move in and out by diffusion.
What types of molecules can diffuse through cell membranes?
Only very small molecules can diffuse through cell membranes, such as:
* oxygen
* glucose
* amino acids
* water
Which large molecules cannot fit through cell membranes?
Big molecules like starch and proteins cannot fit through the membrane.
How does diffusion occur across cell membranes?
Particles flow from areas of higher concentration to areas of lower concentration.
What happens to particle movement across a cell membrane?
Particles move randomly, but there is an overall movement from the side with more particles.
How does surface area of a membrane affect diffusion rate?
The larger the surface area of the membrane, the faster the diffusion rate.
