| Pump Class | Energy Source | Key Examples | Primary Function | |------------|---------------|---------------|--------------------| | | ATP (autophosphorylation) | Na⁺/K⁺ ATPase, Ca²⁺ ATPase, H⁺/K⁺ ATPase | Ion gradients (nerve, muscle, stomach acid) | | F-type ATPase | Proton motive force (usually reverse of ATP synthesis) | ATP synthase in mitochondria/chloroplasts | Makes ATP (usually not a pump, but reversible) | | V-type ATPase | ATP | Vacuolar H⁺ ATPase | Acidifies organelles (lysosomes, endosomes) | | ABC Transporter | ATP | MDR1 (multidrug resistance protein), CFTR | Pumps wide variety of substrates (drugs, lipids, ions) |
Active transport is vital for maintaining specific internal environments within cells and is generally classified into two main types based on how energy is harnessed: active transport protein pump