Membrane Transport and Facilitated Diffusion

A collection of flashcards on membrane transport processes including active transport mechanisms, types of pumps, endocytosis, and exocytosis.

Active Transport

Transport of a molecule that requires energy because it moves a solute against its concentration gradient (low to high).

Adenosine Triphosphate (ATP)

Energy source used by cells that can transfer a phosphate group to a transport protein, changing its shape to move substances.

Membrane Potential

Unequal concentrations of ions across the membrane which results in an electrical charge (electrochemical gradient).

Sodium Potassium Pump

A pump that regulates the concentrations of sodium (Na+) and potassium (K+) by pumping 3 Na+ out of the cell and 2 K+ into the cell.

Proton Pump

An integral membrane protein that builds up a proton gradient across the membrane, important for ATP generation.

Exocytosis

The secretion of molecules via vesicles that fuse to the plasma membrane, releasing their contents to the extracellular fluid.

Endocytosis

The uptake of molecules from vesicles that fuse from the plasma membrane; includes phagocytosis and pinocytosis.

Phagocytosis

A type of endocytosis where a cell engulfs particles to be digested by lysosomes.

Pinocytosis

Nonspecific uptake of extracellular fluid containing dissolved solutes.

Receptor-Mediated Endocytosis

Specific uptake of molecules via solute binding to receptors on the plasma membrane, allowing for uptake of large quantities of specific substances.