Active Transport Terms

Active Transport

The movement of solutes across a cell membrane against their concentration gradient, requiring cellular energy (ATP).

Primary Active Transport

A transport process that directly uses chemical energy (ATP hydrolysis) to pump solutes against their concentration gradient.

3 Sodium out, 2 Potassium in

Sodium Potassium Pump

Phosphorylation

The addition of a phosphate group to a protein triggered by ATP breakdown, causing a conformational change.

Dephosphorylation

The release of a phosphate group from a protein, causing it to revert to its original shape.

Resting Membrane Potential

The negative electrical charge maintained inside a cell relative to the outside at homeostasis.

Secondary Active Transport

Transport that indirectly uses energy from an established ionic concentration gradient to move another molecule against its gradient.

Symport

A cotransport mechanism where two substances move across the membrane in the same direction.

Antiport

A cotransport mechanism where two substances move across the membrane in opposite directions.

Vesicular Transport

Transport of large particles, fluids, or macromolecules across the plasma membrane using membranous sacs.

Endocytosis

The process of bringing extracellular contents into the cell by membrane invagination.

Receptor Mediated Endocytosis

Highly selective. Specific extracellular ligands bind to membrane receptors, triggering aggregation in clathrin-coated pits to form an endocytic vesicle.

Phagocytosis

Engulfment of large solid particles or pathogens by pseudopods to form a phagosome.

Pinocytosis

Non-selective fluid phase endocytosis. The cell continuously samples droplets of extracellular fluid without using clathrin or specialized receptors.

Exocytosis

Secretory vesicles fusing with the plasma membrane to release contents into the extracellular space.

v SNARES

Specific vesicle-bound proteins on the secretory membrane.

t SNARES

Target proteins located on the cytosolic surface of the plasma membrane.

pseudopods

This is what drives Phagocytosis

Phagosome

What is formed (the actual vesicle) for phagocytosis