Topic 1 - Diffusuion, Osmosis, Active Transport Flashcards
What is diffusion?
The overall movement of particles from an area of higher concentration to an area of lower concentration.
Where does diffusion happen?
In liquids and gases because the particles can move about randomly.
What is osmosis?
The net movement of water molecules across a partially permeable membrane from higher water concentration to lower water concentration.
What can pass through the membrane?
Water, it passes both ways as water molecules move about randomly.
What is active transport?
The movement of particles across a membrane against a concentration gradient using energy transferred during respiration.
Example of where active transport happens
In the digestive system when there’s a higher concentration of nutrients in the gut than the blood the nutrients diffuse naturally into the blood.
What does active transport allow to happen?
Allows nutrients to be taken into the blood despite the concentration gradient being the wrong way. This stops us starving.
How do you find the percentage change in mass in osmosis?
Percentage change = final mass - initial mass / initial mass x 100
