Transport Mechanisms Across Membranes

These flashcards cover key concepts related to transport mechanisms across cell membranes, including definitions and functions of various transport processes.

Osmosis

The diffusion of water through a membrane from an area of lower solute concentration to an area of higher solute concentration.

Diffusion

The random movement of molecules from an area of higher concentration to an area of lower concentration.

Endocytosis

The process where a cell engulfs material from the outside environment by wrapping it in a segment of its plasma membrane.

Exocytosis

The process where a cell expels materials in vesicles that fuse with the plasma membrane.

Hypertonic solution

A solution that has a higher solute concentration than the cytoplasm of the cell, causing the cell to lose water.

Hypotonic solution

A solution that has a lower solute concentration than the cytoplasm of the cell, causing the cell to gain water and swell.

Isotonic solution

A solution that has the same solute concentration as the cytoplasm of the cell, resulting in no net movement of water.

Active transport

The process of moving molecules across a membrane against their concentration gradient, requiring energy.

Facilitated diffusion

The process of transporting substances across a cell membrane via protein channels or carrier proteins along their concentration gradient, without energy.

Aquaporin

A channel protein in the membrane that facilitates the transport of water.

ATP (Adenosine triphosphate)

The primary energy carrier in all living organisms.

Channel proteins

Proteins that provide passageways for ions and small molecules to cross membranes.