Exocytosis is active transport of molecules out of cells using energy. Process occurs via porosomes at cell plasma membrane. Term proposed by De Duve in 1963
Active transport moves molecules against concentration gradient using cellular energy. Primary active transport uses ATP, secondary uses electrochemical gradient. Essential for nutrient uptake, hormone secretion and nerve impulse transmission
Concentration gradient is the gradual change in solute concentration over distance. Results from unequal distribution of particles between intracellular and extracellular fluids. Solutes move from high to low concentration areas to establish equilibrium
Plasma membranes are 5-10 nm thick and form a fluid mosaic model. Main components include phospholipids, cholesterol, proteins, and carbohydrates. Phospholipids have hydrophilic heads and hydrophobic tails. Cholesterol is present in the membrane's core
Cell membranes are semi-permeable, allowing only certain molecules to pass. Active transport moves substances against concentration gradient using ATP. Mutations in transporters can lead to various health conditions
Active transport moves molecules against concentration gradient using cellular energy. There are two types: primary (ATP-driven) and secondary (electrochemical gradient). Primary transport uses ATP pumps, secondary uses electrochemical gradient