Topic 1 Diffusion % Flashcards
What is diffusion
Movement of particles from an area of high concentration to an area of low concentration
What substances does diffusion happen in
Both solutions and gases because the particles in a substance are free to move about randomly
What makes the diffusion rate faster
The bigger the concentration gradient the faster the diffusion rate
I higher temperature will also give a faster diffusion rate because the particles have more energy to move faster
Which way do the particles move in diffusion
The particles move down a concentration gradient with NO ENERGY REQUIRED
Where does diffusion occur
The lungs within the body - Oxygen defuses from the alveoli into the blood and carbon dioxide diffuses from the blood into the alveoli
Leaves on a plant- Carbon dioxide from the stomata diffuses into the leaves and finally into the cells Whilst oxygen is let out during gaseous exchange
Urea diffusers from cells into the blood plasma for removal from the body by the kidneys
What can fit through the cell membrane
Small molecules can diffuse through a cell membrane such as oxygen, glucose, amino acids and water
What can’t fit through a cell membranes
Big molecules like starch and protein
When do particles diffuse through the cell membrane
They move randomly so can go both ways but are more likely to go from a higher concentration to where there’s a lower concentration
What increases diffusion
The larger the surface area of the membrane the faster the diffusion rate because more particles can pass through at once
