Membrane Transport Processes

Vocabulary flashcards covering key terms related to membrane transport processes.

Diffusion

The net movement of molecules from an area of high concentration to an area of low concentration.

Osmosis

A special case of diffusion that describes water movement across a selectively permeable membrane.

Isotonic solution

A solution that has the same concentration of solutes as another solution, resulting in no net movement of water.

Hypotonic solution

A solution that has a lower concentration of solutes compared to another solution, causing cells to swell.

Hypertonic solution

A solution that has a higher concentration of solutes compared to another solution, causing cells to shrink.

Passive transport

Movement of substances across a cell membrane without the use of energy.

Active transport

Movement of substances across a cell membrane that requires energy, often against a concentration gradient.

Facilitated diffusion

Transport of substances across a cell membrane via a protein channel or carrier, without energy expenditure.

Primary active transport

Active transport that directly uses ATP to move substances against their concentration gradient.

Secondary active transport

Active transport that uses energy stored in a concentration gradient created by primary active transport.

Endocytosis

The process by which cells internalize substances by engulfing them in vesicles.

Exocytosis

The process by which cells release substances from vesicles into the extracellular fluid.

Transcytosis

A combination of endocytosis and exocytosis to move substances across a cell.

Carrier-mediated transport

Transport processes that involve specific membrane proteins to move molecules across membranes.

Concentration gradient

The difference in the concentration of a substance between two areas.

Membrane channels

Protein structures that create pathways for specific molecules to pass through the cell membrane.

Phagocytosis

A specific type of endocytosis where cells engulf large particles or organisms.