CB1h Transporting Substances Flashcards
What are solutes?
Dissolved substances
What is diffusion?
The movement of particles from a high concentration to low concentration, it is a passive process. Along the concentration gradient. If particles are small enough to move through a partially permeable membrane then diffusion will take place.
What is osmosis?
The movement of water particles through a partially permeable membrane, from a dilute solution to concentrated solution.
Key points of diffusion
Solute Molecules
Can occur in gases, liquids and cell membranes
From high concentration to low concentration
Passive, requires no energy
Key points of osmosis
Solvent molecules
Across semi-permeable membrane
From where there are more solvent molecules in a give volume to where there are fewer
From dilute solution to concentrated solutions
Passive, requires no energy
Key points of active transport
Solvent molecules Across cell membrane using transporter proteins Against concentration gradient Higher to Lower concentration Active, requires energy
What is active transport?
The movement of molecules across a cell membrane, from where they are LOWER in concentration to where they are HIGHER in concentration, AGAINST the concentration gradient
What does Active Transport use to carry molecules?
Active transport uses transporter proteins to carry molecules through the cell membrane against their concentration gradient. This process needs energy to change the shape of the protein.
How does Active Transport take place?
A molecule sticks to the transporter protein, energy is given, the transporter protein carries the molecule across the cell membrane.
