Cell Structure and Membrane Transport

Flashcards covering key vocabulary related to cell structure and membrane transport mechanisms.

Vesicle

A small, membrane-bound sac that transports substances into and out of the cell.

Endocytosis

The process by which a cell engulfs external material, incorporating it into vesicles.

Exocytosis

The process where a vesicle fuses with the cell membrane to release its contents to the outside of the cell.

Osmosis

The diffusion of water across a selectively permeable membrane.

Diffusion

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

Pinocytosis

A form of endocytosis where the cell takes in small droplets of extracellular fluid.

Phagocytosis

A form of endocytosis that involves the intake of large particles or microorganisms.

Receptor-assisted endocytosis

A process where specific molecules are brought into the cell after binding to receptor proteins.

Active transport

The movement of molecules against their concentration gradient, requiring energy input from the cell.

Facilitated diffusion

A passive transport process aiding the movement of molecules across the cell membrane via specific carrier proteins.

Carrier protein

A membrane protein that helps transport specific substances across the cell membrane.

Channel protein

A membrane protein that forms a tunnel-like structure, allowing ions and small molecules to pass through.

Selectively permeable

A characteristic of cell membranes that allows certain substances to pass while restricting others.

Phospholipid bilayer

The fundamental structure of cell membranes, consisting of two layers of phospholipids.

Cytoplasm

The gel-like substance within the cell membrane where cell components are suspended.

Nucleus

The membrane-bound organelle that contains the cell's genetic material (DNA).