Membrane Transport

Flashcards generated from notes on membrane transport, covering key concepts and vocabulary related to the topic.

Plasma Membrane

A selectively permeable barrier that controls the entry and exit of molecules.

Passive Transport

Movement of molecules across a membrane without the input of energy, occurring down the concentration gradient.

Active Transport

Movement of molecules against their concentration gradient, requiring energy input.

Osmosis

The diffusion of free water across a selectively permeable membrane.

Tonicity

The ability of a surrounding solution to affect the volume of a cell by causing it to gain or lose water.

Isotonic

A solution where concentrations of solute and water are equal on both sides of a membrane.

Hypertonic

A solution with a higher solute concentration, leading to water loss from the cell.

Hypotonic

A solution with a lower solute concentration, leading to water gain in the cell.

Facilitated Diffusion

The process by which molecules pass through a membrane via transport proteins, down their concentration gradients.

Ion Channels

Transmembrane proteins that allow ions to pass through the membrane in response to a stimulus.

Electrogenic Pump

A transport protein that generates a voltage across a membrane, such as the sodium-potassium pump.

Uniporter

A transporter that moves a single molecule or ion across a membrane.

Symporter

A transporter that moves two or more ions or molecules in the same direction across a membrane.

Antiporter

A transporter that moves two or more ions or molecules in opposite directions across a membrane.

Exocytosis

The process where materials packaged in vesicles are expelled from the cell into the extracellular space.

Endocytosis

The process by which cells internalize substances from their external environment by engulfing them.

Phagocytosis

A form of endocytosis in which a cell engulfs solid material.

Pinocytosis

A form of endocytosis where a cell ingests liquid from the surrounding environment.

Receptor-Mediated Endocytosis

A targeted form of endocytosis where substances are taken in after binding to receptors on the cell membrane.

Familial Hypercholesterolemia

An inherited condition caused by defective LDL receptors, leading to high cholesterol levels in the blood.