Year 9 stuff Flashcards
What is diffusion?
Diffusion is the net movement of particles from an area of high concentration to an area of low concentration .
Which direction to particles normally diffuse to?
The area with the least amount of particles.
What do molecules do if they are left alone?
They move around randomly.
Which states can molecules diffuse?
Liquids and gasses.
What does partially permeable mean?
Only some molecules can pass through the membrane.
Which molecules are able to diffuse into and out of cells?
Glucose, water and amino acids
What affects the rate of diffusion?
Temperature, surface area and concentration gradient
Will a larger surface area increase or decrease the rate if diffusion?
Increase because a larger surface area means a larger area over which molecules can diffuse.
Why does a higher temperature increase the rate of diffusion?
Higher temp means particles have more energy (kinetic). This means they move around faster and diffusion happens quicker.
What is the definition of osmosis?
Osmosis is the net movement of water molecules across a partially permeable membrane, from a region of high water concentration to a region of low water concentration.
The partially permeable membrane is usually the….?
Cell membrane
Osmosis is the movement of which molecules?
Water
Which way does water move?
Down the concentration gradient
What would happen if red blood cells were placed in pure water?
They would gain water and swell
What is active transport?
Active transport is the movement of molecules across a membrane, from a region of low concentration to a region of high concentration. This requires energy from respiration, and so this is an active process.
