Types of transport Flashcards
what is diffusion?
Diffusion is the movement of molecules from an areas of high concentration to an area of lower concentration down a diffusion gradient.
- Diffusion does not require energy - it is a passive process.
what types of molecules travel via diffusion ?
Small molecules like O2 and CO2
What is facilitated diffusion?
Facilitated diffusion occurs when proteins are used to transport molecules down a concentration gradient. Large molecules and charged particles (like ions) move via facilitated diffusion.
example of facilitated diffusion
molecules moving via Channel proteins or Carrier proteins
what is active transport?
Active transport is the movement of particles against a concentration gradient. This means that the molecules move from a low concentration to a high concentration.
- Active transport requires energy in the form of ATP.
what type of proteins does active transport use?
Active transport uses proteins with a specific shape to move particles. The shape of the protein changes when the molecule is moved through, so there is no backflow.
what is Endocytosis & Exocytosis
When large quantities of materials need to be moved into cells endocytosis can occur. When large quantities of materials need to be moved out of cells exocytosis can occur.
how does Endocytosis & Exocytosis work?
These process happen when the membrane is moved to form small packets called vesicles. This requires energy in the form of ATP.
what is osmosis
Osmosis is the diffusion of water molecules.
- osmosis is the movement of water molecules from a region of high water potential (When the water concentration is high, the water potential is higher) to a region of low water potential through a partially permeable membrane.
what is water potential ?
When the water concentration is high, the water potential is higher.
