1.4 - Membrane support Flashcards
What is passive transport?
higher concentration —> lower concentration
doesn’t require energy
What is active transport?
lower concentration —> higher concentration
requires energy (ATP)
What is diffusion?
passive net movement of particles from areas of high concentration to low concentration (often through a partially permeable membrane)
What is simple diffusion?
passive transport
molecules move between phospholipids
What is facilitated diffusion?
passive transport
molecules move through proteins that change shape to allow them to go through
What is osmosis?
type of facilitated diffusion, the passive movement of water between a semi-permeable membrane
What is osmolarity?
measure of solute concentration defined by the number of osmoles of a solute per litre of solution
What is a hypotonic solution?
solution with lower concentration of solutes
What is a hypertonic solution?
solution with higher concentration of solutes
What is an isotonic solution?
solution in both sides of the membrane is equal
What factors make the movement of molecules easy?
small, non-polar molecules (O2, CO2)
What factors make the movement of molecules difficult?
large, polar molecules (ions, glucose)
What is Sodium Potassium Pump?
active transport pump (tunnels) that exchanges sodium ions for potassium ions
What are factors affecting the role of diffusion through a partially permeable membrane?
- concentration gradient
- surface area
- length of diffusion path
