diffusion and active transport

diffusion

molecules moving from high concentration to low concentration across a concentration gradient

simple diffusion

movement of molecules from high to low concentration down a concentration gradient using no additional energy (ATP)

characteristics of simple diffusion

non polar molecules

moves between phospholipids in the bilayer

facilitated diffusion

movement of molecules from high to low concentration down concentration gradient through intrinsic proteins (carrier and channel proteins) going through hydrophilic bilayer using no additional energy (ATP)

characteristics of facilitated diffusion

polar molecules

uses carrier and channel proteins

differences between simple and facilitated diffusion

simple uses non polar molecules whereas facilitated uses polar molecules

simple cannot pass through phospholipids bilayer whereas facilitated diffusion can

facilitated diffusion uses intrinsic proteins

similarities of simple and facilitated diffusion

move down concentration gradient

both do not require additional energy (ATP)

active transport

movement of ions against concentration gradient through carrier proteins requiring additional energy (ATP)

ATP is used to change shape of carrier protein

difference of diffusion and active transport

active transport required additional energy (ATP)

difference between carrier and channel protein

carrier proteins change shape

channel proteins lines with hydrophilic amino acids

fluid mosaic model

made up of a phospholipid bilayer with hydrophilic phosphate head face outward with hydrophobic fatty acid tail on the inside

intrinsic proteins which allow for diffusion and active transport

glycolipids

glycoproteins

extrinsic protein carbohydrate