Human Biology 2.2 Active Transport

Electrochemical Gradient

combined electrical and chemical force that produces a gradient

inside of cell is negatively charged, therefore positively charged molecules are attracted to cell and pushed through membrane

Pump

active transport mechanism that works against electrochemical gradients

Primary Active Transport

moves ions or small molecules across a membrane and creating an ion gradient across the membrane

requires ATP

Secondary Active Transport

movement of molecules across a membrane as a result of the change cause by primary active transport

energy comes from ion gradient, no ATP used

Transporter

specific carrier protein or pump that facilitates movement

Uniporter

transporter that carries one specific ion or molecule

Symporter

transporter that carrier two ions or molecules

both in the same direction

Antiporter

transporter that carries two ions or molecules

in different direction

Electrogenic Pump

pump that creates a charge imbalance

Endocytosis

type of active transport that moves large particles into the cell

cell membrane engulfs particle, pulls it into the cell, and pinches off to release the new vesicle into the cell

Phagocytosis

cell takes in large particles such as debris, bacteria, or dead cells

typically performed by white blood cells

Pinocytosis

cell takes in extracellular fluid which contains water and dissolved molecules

Potocytosis

cell takes in small molecules using caveolae on the membrane that releases the molecules on the other side

Receptor Mediated Endocytosis

form of endocytosis the uses specific binding proteins to bring their respective molecules through the cell membrane

Exocytosis

process of expelling molecules from the cell into the extracellular fluid

waste is enveloped in membrane and then fuses to the cell’s membrane, waste is moved to exterior