Chapter 5 Flashcards
what is passive transport
movement of molecules down their concentration gradient, no energy needed
what are examples of passive transport
simple, facilitated diffusion, and osmosis
what is simple diffusion
allows molecules to cross the membrane w/o aid of membrane proteins
what is facilitated diffusion
allows molecules to cross the membrane with help of membrane proteins (channels/carriers)
what is osmosis
diffusion of water down its concentration gradient
what are the types of osmosis
isotonic, hypertonic, and hypotonic
isotonic
concentration of solutes and cell are the same
hypotonic
higher solute outside, more water inside, water moves out and shell shrivles up
hypertonic
higher solute inside and more water outside so water moves in and blows up
active transport
movement of molecules up their concentration gradient with help of energy
what are the two types of active transport
cotransport (symport) and countertransport (antiport)
cotransport (symport)
membrane transport that carries 2 substances in same direction across membrane
what is a good example of cotransport
Na+/glucose transporter (uses Na+ gradient established by Na/K pump as a source of energy) to move Na and glucose into the cell
countertransport (antiport)
membrane transport that carries one substance in one direction and another in the opposite direction
Endocytosis
energy using process by which cells import substances from the external medium
