Cell Transport Flashcards
What is facilitated diffusion?
Diffusion through special protein channels
What is passive transport?
Movement of materials across the cell membrane without using cellular energy
What is osmosis?
Diffusion of water through a selectively permeable membrane
What is an isotonic solution?
both solutions have equal concentrations of solutes
What are the functions of the cell membrane?
protect the cell, control incoming and outgoing substances, maintain ion concentrations of various substances, allows some molecules in and others out
What is a selectively permeable membrane?
a membrane that allows some molecule in and keeps others out
What are the four basic mechanisms of transport through cell membranes?
- Diffusion and Facilitated Diffusion
- Osmosis
- Active Transport
- Endocytosis and Exocytosis
What is diffusion?
the movement of molecules (or ions) from a region of high concentration to a lower concentration
Molecules move about randomly because of what?
kinetic energy
When do molecules reach equilibrium?
when hey are evenly spread out
What is an hypotonic solution?
solution with the lesser concentration of solutes
What is a hypertonic solution?
solution with higher concentration of solutes
What is active transport?
transport of a molecule in or out of cell that requires energy
