AP Biology Unit 2 Topics 6,7,9 Membrane Transport, Facilitated Diffusion, Mechanisms of Transport

These flashcards cover key vocabulary related to the transport mechanisms across cell membranes, including selective permeability, types of transport, and specific processes involved in moving substances in and out of the cell.

Selective Permeability

A property of cell membranes that allows certain substances to cross more easily than others.

Passive Transport

The movement of molecules across a membrane without the use of energy, moving down their concentration gradient.

Facilitated Diffusion

The process of transporting molecules across a membrane via specific transport proteins, without using energy.

Osmosis

The diffusion of water across a selectively permeable membrane, moving from areas of low solute concentration to high solute concentration.

Active Transport

The movement of molecules across a membrane that requires energy, moving against their concentration gradient.

ATP (Adenosine Triphosphate)

The primary energy carrier in cells, used to fuel active transport processes.

Electrogenic Pumps

Proteins that generate voltage across membranes, contributing to the electrochemical gradient.

Cotransport

The coupling of the favorable transport of one substance with the unfavorable transport of another.

Exocytosis

The process by which a cell secretes materials via vesicles that fuse with the plasma membrane.

Endocytosis

The process by which a cell takes in materials through vesicles that fuse with the plasma membrane.

Phagocytosis

A type of endocytosis in which a cell engulfs large particles, which are then digested by lysosomes.

Pinocytosis

A form of endocytosis where cells take in extracellular fluid and dissolved molecules.

Receptor-Mediated Endocytosis

A selective uptake mechanism where cells target specific molecules via receptors on the plasma membrane.